* Skips setting undefined device id to sink in audio preview.

* Fallbacks to use labels for user selected devices.

* Fixes comment.

* Fix detecting preferred audio output.

Fixes detecting when a new output device is found and we have stored user preference of using that device.

* Does not store which is the currently open device on save.

Does not save the currently opened device when saving settings dialog, this will be done once we successfully replace the tracks to use the new devices.

* Saves opened audio device after successfully changing it.

If we do it earlier _updateAudioDeviceId is using localAudio and can store wrong value.

* Adds notification for new non preferred devices.

A notification is shown which gives an option to the user to select and use the newly plugged devices.
Adding custom button and handler for the action to the notifications.

* Changes logic to search and handle all newly added devices from array.

* Moves some utility methods to features/base/devices.

The state about currently opened devices is filtered and not stored, where we only store when user selects a device preferences.
Also allow changing input devices for Firefox when we are not in a conference.

A libre build will exclude the following:

- Analytics modules
- Google Play services GMS
- Crashlytics
- Firebase

Avoid using a Modal since those create trouble with the view hierarchy.

* Prints errors in case of wrong initialization.

Not printing can masks some errors in the code.

* Allow only one Follow Me moderator in a meeting.

* Sends Follow Me state with all presences of the moderator.

This fixes an issue where the moderator sends the Follow Me state and then for example mute or unmute video (this will produce a presence without Follow Me state) and the new comers will not reflect current Follow Me state till a change of it comes.

* Changes fixing comments.

* Changes fixing comments.

Dear reader, I'm not proud at all of what you are about to read, but sometimes
life just gives you lemons, so enjoy some lemonade!

Joining a conference implies first creating the XMPP connection and then joining
the MUC. It's very possible the XMPP connection was made but there was no chance
for the conference to be created.

This patch fixes this case by artificially genrating a conference terminated
event in such case. In order to have all the necessary knowledge for this event
to be sent the connection now keeps track of the conference that runs it.

In addition, there is an even more obscure corner case: it's not impossible to
try to disconnect when there is not even a connection. This was fixed by
creating a fake disconnect event. Alas the location URL is lost at this point,
but it's better than nothing I guess.

Use subscribers to detect state change and emit those
out to other participants. Use middleware to register
the command listener.

Searching for a device (id) by label alone can result in
false results when devices share labels, such as a mic
and speaker having the same label. To prevent such,
specify the device kind to be found instead of iterating
over all device kinds.

When the iFrame api is used to set a preferred audio output using
options passed into the JitsiMeetExternalAPI constructor, no logic
fires to actually change the audio output destination.

If tracks are created while the conference is in the 'joining' state
they will never be added.

🔥🔥🔥

Using anything non-serializable for action types is discouraged:
https://redux.js.org/faq/actions#actions

In fact, this is the Flow definition for dispatching actions:

declare export type DispatchAPI<A> = (action: A) => A;
declare export type Dispatch<A: { type: $Subtype<string> }> = DispatchAPI<A>;

Note how the `type` field is defined as a subtype of string, which Symbol isn’t.

That's what the SDK passes now, if the room URL is not absolute.

* Updates recording dialog.

* Update config.js doc.

* Adds comment and make a check more intuitive.

* Changes of using enum for recording types.