Keep track of the connection and conference objects so we can leave and / or
disconnect early, before the connection is established or the conference joined.

On mobile we got the extra step of overriding the option and always set it to
true.

Add a menu that displays when hovering over VideoStatusLabel. The menu's
display is controlled by CSS. As the existing AudioOnlyLabel no longer needs
needs its own tooltip, it has been removed and label display logic has been
moved into VideoStatusLabel.

There were getDomain, setDomain, SET_DOMAIN, setRoomURL, SET_ROOM_URL
which together were repeating one and the same information and in the
case of the 'room URL' abstraction was not 100% accurate because it
would exist even when there was no room. Replace them all with a
'location URL' abstraction which exists with or without a room.

Then the 'room URL' abstraction was not used in (mobile) feature
share-room. Use the 'location URL' there now.

Finally, removes source code duplication in supporting the Web
application context root.

Move the HD label into the newly renamed VideoStatusLabel
component. That way it cannot be possible for the audio only
label and the HD label to display simultaneously.

Audio only mode can be used to save bandwidth. In this mode local video is muted
and last N is set to 0, thus disabling all remote video.

When this mode is enabled avatars are shown.

The config object defined by lib-jitsi-meet is not used by
lib-jitsi-meet only, jitsi-meet respects its values as well.
Moreover, jitsi-meet defined classes and/or functions which manipulate
that config object. Consequently, it makes sense to move the config
object and the associated classes and functions in a dedicated feature.

Rename setStateProperties and setStateProperty to assign and set,
respectively. Inspired by Object.assign, _.assign, and _.set.

@virtuacoplenny, the changes of this commit are not necessarily in
source code that you introduced in
https://github.com/jitsi/jitsi-meet/pull/1499 but I saw violations in
files modified in the PR which I had to read in order to understand the
PR.

Converting the invite modal includes the following:
- Creating new react components to display InviteDialog. The
  main parent components are ShareLink and PasswordOverview,
  the later handles displaying lock state and password editing.
  These components do not make use of atlaskit as the component
  for input does not yet support readonly, so for consistency
  within the modal content no atlaskit was used.
- Using redux for keeping and accessing lock state instead of
  RoomLocker.
- Publicly exposing the redux action lockStateChanged for direct
  calling on lock events experienced on the web client.
- Removing Invite, InviteDialogView, and RoomLocker and references
  to them.
- Handling errors that occur when setting a password to preserve
  existing web funtionality.

JitsiConnection.initJitsiConference doesn't automatically pass the global config
options, so grab the config from the Redux store and pass it.

The behavior can be triggered with the toggleAudioOnly action, which is
currently fired with a button.

The following aspects of the conference will change when in audio only mode:

- local video is muted
- last N is set to 0 (effectively muting remote video)
- full-screen mode is exited
- audio mode is set to "audio chat" (default output is the earpiece)
- the wake lock is disengaged

One aspect not handled in this patch is disabling the video mute button while in
audio only mode. The user should not be able to turn back video on in that case.

They better represent if a participant has video available or not. There are
cases when even a participant in the last N set would not have video because it
disconnected momentarily, for example.

This is in preparation for an upcoming "audio only mode" feature. Setting last N
will also be required for it, so this patch factors out the action and makes it
public so other modules can reuse it.

In addition, if the value is set to undefined the configured default value (or
-1 if absent) is picked.

Replaces changeAvatarID, changeAvatarURL and changeEmail with
participantUpdated action.
participantUpdated can be fired for local user without id. This
fixes the problem with updating the local user before the user
join the conference which results in fix for failing to execute
commands for avatarID, avatarURL and email right after the iframe
api creates the iframe with Jitsi Meet.

On RN we don't use the global APP object, so don't save the store there unless
it's defined, which is the case in the current web version. Also, check for
undefined explicitly, since a "if (!APP)" check will throw a ReferenceError.

Includes automatic recommended Xcode project file fixes.

Simplify the source code (with the idea that source code which does not
exist does not have to be maintained).

Additionally, apply modifications to have the source code comply with the coding
style.

Overall, prepare saghul:audio-mode for merge into jitsi:master.

It's fired before creating the conference with lib-jitsi-meet.

As an intermediate step on the path to merging jitsi-meet and
jitsi-meet-react, import the whole source code of jitsi-meet-react as it
stands at
2f23d98424
i.e. the lastest master at the time of this import. No modifications are
applied to the imported source code in order to preserve a complete
snapshot of it in the repository of jitsi-meet and, thus, facilitate
comparison later on. Consequently, the source code of jitsi-meet and/or
jitsi-meet-react may not work. For example, jitsi-meet's jshint may be
unable to parse jitsi-meet-react's source code.