Fixes chrome undefined JS error

Prepare for React Native

Since (1) half of the disco uses check whether the feature in question
is supported, (2) the other half appears to not absolutely require
disco, and (3) disco needs to be explicitly included/required in order
to be supported, make disco completely optional.

Since half of the Settings functions check whether localStorage is
supported, adds the check to the other half to make localStorage
completely optional.

The function filter_special_chars does not have to throw a TypeError
when its argument text is null or undefined because (1) it can be argued
that neither of these two contains special characters and (2) it is much
more convenient to have the check in the function in question rather at
its multiple call sites.

Fix missing hidden domain problem

Don't rely on JitsiMeetJS being global

While we have JitsiMeetJS defined as a global variable in Jitsi Meet, it
doesn't sound like an absolutely necessary and beautiful requirement
inside the library itself.

Define the main/primary entry point of the library

Enables the library to be used via require. Example usage is a React
Native (mobile) app which bundles its dependencies (in its release
build).

Add maxFps option for requesting video

Adds a stereo option.

Lipsync

Add hidden participant support

Rename variables with "stream" in name which refer to JitsiTrack.
Rename TRACK ADDED/REMOVED events.
Try to reduce direct access to remoteTracks object.
Log warning message when track is overwritten.

We were assigning the var, before the type was compared which
could result in accepting "audio" stream for "video" JitsiLocalTrack.

Fixes callstats wrtcFuncNames signalingError.

Sends dominant speaker events to callstats.

Fixes the options object used.

Adds startBitrate to the conference creation request.

Saves the time a data channel was opened in connectionTimes.

Changes JitsiConference.getLocalTracks and JitsiParticipant.getTracks to return cloned array of tracks