Audio only mode will be toggleable only from the VideoStatusLabel,
so remove AudioOnlyButton from the toolbar and delete the component
itself. As a result of the button being removed, a truthy check in
VideoStatusLabel was also removed to ensure it will display as it
is now the only way to toggle audio only mode. Also set the cursor
on VideoStatusLabel to always be default, so it can never show the
text cursor.

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.

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.

Remove toolbar button and icon style literals from the render method of
Toolbox.native.js.

Additionally, comply w/ coding style.

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.

When a new local video track is created an associated video capturer is created
for it. The cause for the freezes seems to be creating mutliple tracks (which
come with a video capturer each). Fix this by first disposing of the previous
video track before creating the new one.

Ref:
https://github.com/oney/react-native-webrtc/issues/209#issuecomment-281482869

It got broken while rewriting the Web toolbar in React Toolbox. There is
a problem with the toolbars and how we construct the intialState of the
buttons. The _getInitialState() in the toolbox reducer gets the list of
buttons from interfaceConfig, but in fact interfaceConfig is meant to be
overriden in several very important cases. One of the cases being the
external API, which we use in several projects in production.