Enables RTPStatsCollector for react-native. The getStats method was
supported long time ago, but the stats produced by the RTPStatsCollector
were not consumed. Now they are needed for the automated testing on RN.

Adds stats and audio levels for Safari. Enables the new getStats API for Firefox, that will get rid of the following warning:
'non-maplike pc.getStats access is deprecated, and will be removed in the near future! See http://w3c.github.io/webrtc-pc/#getstats-example for usage.'

* log: Logs when analytics are disposed, drops events early.

* fix: Adds a missing parameter to a function call.

In order to include browser capabilities in RTCBrowserType I needed to
refactor RTCBrowserType.

Avoid throwing an exception if an analytics handler throws one. Emit a warning
though, so the problem can be eventually caught and fixed in the handler.

* wip: initial version of the new AnalyticsAdapter.

* ref: Restructures the ICE duration and state change events.

* ref: Restructures the JitsiLocalTrack events.

* ref: Restructures the TTFM events.

* ref: Updates the user feedback event.

* ref: Restructures the _CONNECTION_TIMES_ and TTFM events.

* ref: Restructures the BRIDGE_DOWN and NO_DATA_FROM_SOURCE events.

* ref: Restructures the FOCUS_LEFT event.

* ref: Restructures the DATA_CHANNEL_OPEN event.

* ref: Removes the ICE_FAILED event (it is a duplicate of a state change event).

* ref: Restructures the device list events.

Uses one event per device, since the new format does not allow non-atomic attributes.

* fix: Does not obey "unmute" commands from the focus.

* ref: Restructures the "remotely muted" event.

* ref: Restructures the CONFERENCE_ERROR events.

* ref: Removes the CONNECTION_INTERRUPTED event

We can use ICE_STATE_CHANGED instead.

* ref: Renames isreconnect to isReconnect.

* ref: Removes the CONNECTION_RESTORED event. Use ICE state changes instead.

* ref: Restructures the p2p events.

* ref: Restructures the jingle events.

* ref: Restructures the RTP statistics event.

* ref: Restructures the CONNECTION_FAILED and DISCONNECTED events.

* ref: Restructures the getUserMedia analytics events.

* ref: Cleans up AnalyticsEvents and restructures some of the events.

* fix: Adds error logs to the analytics adapter.

* ref: Refactor Statistics.sendEventToAll

Renames to sendEventAndLog, supports the object-based API, uses the
function where appropriate.

* fix: Addresses PR feedback.

* fix: Addresses Lyubomir's feedback.

* ref: Remove unused functions, adds documentation.

* feat: Adds a Statistics.sendAnalytics shortcut.

* ref: Uses the conference name as the default containerId.

* fix: Adrdesses Lenny's feedback.

* fix: Addresses more feedback.

* fix: Uses 'operational' as the default event type.

* doc: Updates the documentation.

* fix: Fixes adding of permanent properties.

* ref: Uses consistent naming for events' attributes.

Uses "_" as a separator instead of camel case or ".".

* feat: Adds the conference name as a permanent property automatically.

* ref: Don't expose Setting.machineId.

* fix: Adds a "p2p" attribute to jingle events.

* ref: Uses "action" instead of "name".

* ref: Uses underscore in events' attribute names.

* ref: Logs a message to the logger/console

instead of callstats in sendAnalyticsAndLog().

* Passes getWiFiStatsMethod to callstats.

* Prints WiFi addresses on attachWifiStatsHandler.

* Updates callstats version to 3.27.0.

Adds rtc.LOCAL_TRACK_SSRC_UPDATED event to be emitted when ssrc is updated for a local track.
Fixes adding rtc listeners for CREATE_ANSWER_FAILED, CREATE_OFFER_FAILED, SET_LOCAL_DESCRIPTION_FAILED, SET_REMOTE_DESCRIPTION_FAILED.

In case backend was initialized before creating our Callstats instance, we skip calling the callstats method addNewFabric.

* ref: Simplifies the logic for handling an incoming jingle session-initiate.

* fix: Don't redundantly log cross region

information under a field name called "label".

* cleanup: Simplifies code. Adds the userAgent as a permanent property

for statistics (so that the client doesn't have to).

* ref: Names the parameter which specifies the name of the event "eventName".

* ref: Extracts event names to AnalyticsEvents.

* ref: Exports and imports constants individually.

* fix: Fixes CONNECTION_TIMES event names.

* ref: Arranges constants alphabetically.

* ref: Adds line breaks.

AnalyticsAdapter is initialized on file load. The constructor
calls a method that calls Object.assign. All this happens
before jitsi-meet has loaded polyfills. So, instead
initialize permanentProperties inline with the expected
values, avoiding Object.assign.

* Loads CallStats backend only after the script has finished downloading.

* Updates jsdoc and log level.

* Updates jsdoc.

* Uses optional statsId to report to callstats and push it to presence.

The feature is behind a flag which is disabled by default.

* Renames statsId to statsID.

* Fixes doc.

ESLint 4.8.0 discovers a lot of error related to formatting. While I
tried to fix as many of them as possible, a portion of them actually go
against our coding style. In such a case, I've disabled the indent rule
which effectively leaves it as it was before ESLint 4.8.0.

Because the implementation of LocalStorage in jitsi-meet at the time
of this writing is asynchronous with respect to loading and saving,
delay the generation of machineId in order to allow LocalStorage to
load any previously saved value.

There are whole objects logged and the react-native app would crash when
logging too much stuff.

It's no longer needed, and it hasn't been for a while.

This commit changes the way the average stats are being reported to the
analytics backend. Instead of prefixes for the different scenarios
("p2p_", "jvb121_" and no prefix for multi-party calls) we now have
properties that allow to distinguish which scenario an event pertains
to. The query language of the analytics backend can be used to build
appropriate queries that group by those properties.

Additionally, we now report whether the average stats event concerns a
relayed call (a call that's routed via a TURN server) or not.

The JVB121 stats calculators should reset on transition from P2P to
JVB121 conference type.

Will report stats for one to one JVB conference under different prefix.

Tries to batch as many reports as possible into single analytics event
and sends all of them under "avg.rtp.stats" event name.

Also converts dots to underscores in all of the stat names, because now
they become JSON keys where dots are not allowed.

Will also log samples next to the average value for debugging purposes.

* feat: multiple, simultaneous RTP stats

Makes it possible to have remote RTP stats running for more than one
peerconnection at a time.

* feat(stats): report RTT all the time

Will report JVB RTT (and end to end) while in P2P mode and vice versa.

* fix(JitsiConferenceEvents): remove CONNECTION_STATS

CONNECTION_STATS event is no longer emitted.

* fix(AvgRTPStatsReported): users with no video

Do not include FPS == 0 in average remote FPS calculation. Report NaN
for local FPS when video muted or no video device. NaN will be reported
for avg remote FPS if no video is received.

* fix(AvgRTPStatsReported): reset total packet loss

* feat(AvgRTPStatsReported): report 'screen' FPS

Will report average FPS for screen videos separately from camera videos,
but only if available (camera video reports NaN FPS when not available).

* fix(AvgRTPStatsReported): end2endRTT

Needs to report JSON with value.

* feat(AVG RTP stats): separate audio and video bitrate

Will report average audio and video bitrates separately.

* doc(JitsiConference): try to improve comment

* fix(AvgRTPStatsReporter): remove confusing reset

There's no a clear reason for doing reset there.

* ref(AvgRTPStatsReporter): rename var

* ref: store SSRCs as a number

Converts all the places where SSRCs where stored as string to use
numbers.

* doc(RTPStatsCollector): getNonNegativeStat

Fixes invalid description about returning NaN.

* ref(JitsiConf...EventManager): simplify for..of

* ref(JitsiRemoteTrack): throw TypeError

Will throw a TypeError when 'ssrc' is not a number.

* fix(RTPStatsCollector): invalid reference

* doc(RTPStatsCollector): getNonNegativeStat private

* ref(RTPStatsCollector): simplify for..of

* fix(SSRCs): check for negative value

Will not accept negative SSRCs, since those are supposed to be unsigned.

Average end to end RTT calculated as a sum of local RTT towards the JVB
and an average of towards JVB RTTs reported by other participants.
Will be reported under 'stat.avg.end2endrtt' analytics event name.

If the current browser does not support given stat no error should be
printed.

The peer count excludes the current user, so it should be 1 not 2.

AvgRTPStatsReporter will calculate arithmetic means of 'n' samples
and submit the values to the analytics module. The 'n' value is
configurable through 'avgRtpStatsN' conference config option. When set
to non-positive value the AvgRTPStatsReporter will be disabled.

The following values are reported:
- average upload bitrate => 'stat.avg.bitrate.upload'
- average download bitrate => 'stat.avg.bitrate.download'
- average upload bandwidth => 'stat.avg.bandwidth.upload'
- average download bandwidth => 'stat.avg.bandwidth.download'
- average total packet loss => 'stat.avg.packetloss.total'
- average upload packet loss => 'stat.avg.packetloss.upload'
- average download packet loss => 'stat.avg.packetloss.download'
- average FPS for remote videos => 'stat.avg.framerate.remote'
- average FPS for local video => 'stat.avg.framerate.local'
- average connection quality as defined by
  the ConnectionQuality module => 'stat.avg.cq'

If the conference runs in P2P mode 'p2p.' prefix will be added to
the event's name. Any pending calculations are wiped out on every switch
between P2P and JVB modes and samples have to be collected from
the start.

Temasys supports peer connection's getStats.

Webpack 2 defines module.exports as a read-only property in ES6 modules.

We ignore stats that were remotely calculated and take into account only local one.

Internet Explorer is throwing an error when doing a for...of over
Sets. This is because IE needs a Set polyfill, which may be applied
after lib-jitsi-meet has loaded. However, lib-jitsi-meet on load
creates two Sets, one for CallStats.fabrics and another for
Statistics.instances. When the polyfill is then applied, the two
existing Sets do not get new methods. The fix is to lazily
initialize the Sets to allow for polyfills to be applied.

Webpack 2 defines module.exports as a read-only property in ES6 modules.

Will emit BEFORE_STATISTICS_DISPOSED event, before the last CallStats
fabric is terminated to make sure that the final logs batch is reported
correctly.

Also adds a check for CallStats instance to queue events when
the backend has been initialized, but there is no CallStats instance
available to report on.

* ref(CallStats): cleanup constructor

Changes CallStats constructor to not take the whole JingleSessionPC as
it only needs an alias and the TraceablePeerConnection instance.

Describes the arguments in JSDoc.

* ref(CallStats): rename var

Everything is callstats c'mon...

* ref(CallStats): remove _checkInitialize

The _checkInitialize was trying to workaround CallStats lib issue
without really checking for any specific type of error on whether or not
it makes sense to retry.

Also it depended on some internal fields of 'callStatsBackend' and was
binding 'initCallback' to the backend instead of CallStats instance
which made no sense (it means it's very likely this functionality was
broken anyway).

It would be hard to fix it in a clean way, because CallStats instance
fields would have to be stored in static variables in order to make
the initCallback work (called from '_checkInitialize').

We also need to have more than one CallStats instance running at the
same time, because of the P2P which makes things even more complex.

* fix(CallStats): do not catch 'sendApplicationLog'

Wrapping 'sendApplicationLog' in 'tryCatch' will result in an endless
loop, because it will be logged on the logger.error which then tries
to send the logs immediately again.

* ref(CallStats): do not use call on static

There's nothing more confusing that seeing 'this' in a static method.
Wow maybe these methods are not really static !?

* ref(stats): fix var name

* feat(stats): report P2P to CallStats

Will create new CallStats fabric for the P2P peerconnection in order to
log peer to peer connections.

Refactoring was required in the statistics and CallStats module to be
able to have more than one CallStats instance. Because each CallStats
fabric reports one peer connection now each CallStats will correspond to
one TraceablePeerConnection. CallStats instances are now stored in a Map
mapped by the TraceablePeerConnection.id field.

In order to be able to execute some global/static CallStats reporting
methods all Statistics instances also need to be stored in a static
field.

CallStats API backend(new callstats()) will be initialized only once for
the values provided in the first call to initializeBackend. It is not
possible to have more that one CallStats backend running at the same
time (at the time of this writing). If we would have a routine for
disposing global "Statistics" module we could try to cleanup static
reference and allow to initialize it with new values (but no such use
case yet).

* ref(CallStats): move initCallback

Since there is no alphabetic order preserved in this file anyway at
least place it closer to it's usage.

* ref(CallStats): remove tryCatch

Temporarily removes tryCatch to make the ES6 conversion easier.

* ref(CallStats): convert to ES6

* style(CallStats): fix indentation

* fix(statistics): use import for CallStats

* ref(CallStats): convert static methods

Some of the methods should not be static, because it only make sense
to call it when there is CallStats instance available.

* ref(CallStats): rename var

* doc(CallStats): remove misplaced comment

* chore(CallStats): remove invalid eslint comment

* fix(CallStats): undefined CallStats namespace

If no CallStats ID namespace option is provided the conference will be
reported without it.

* style(stats|CallStats): remove extra lines

* fix(CallStats): do not log error from tryCatch

GlobalOnErrorHandler calls logger.error anyway.

* fix(CallStats): cleanup tryCatch

If I understand correctly our initial intention with doing tryCatch was
to avoid crashing the whole app in case the CallStats backend would
crash. With this commit the tryCatch is done by wrapping original
backend instance methods or using explicit try catch block where
the method is called only from one place or a value needs to be returned
in case of a crash.

* ref(CallStats): make backend a static var

* fix(CallStats): invalid eslint comments

* ref(CallStats): use for..of

* ref(CallStats): fixes around REST args

* ref(CallStats): rename var

* ref(CallStats): reorder static methods

Also renamed some callbacks

* doc(CallStats): adds some docs

* ref(CallStats): make methods not static

Both 'sendDominantSpeakerEvent' and 'sendScreenSharingEvent' methods are
not really static as they require instance to be called.

* fix(CallStats): invalid key

* fix(CallStats): reduce amount of debug logs

* feat(p2p|CallStats): log hold/resume

Will put CallStats fabric for the JVB connection "on hold" while in p2p
mode.

* doc(CallStats): add FIXME

* doc(JitsiConference,CallStats): typos and renaming