Brings back the button for generating meeting URLs for calendar events.

Otherwise the participant will not have been added yet
to state so the participant name will not display in
the notification.

When native SDK users end a meeting the view gets disposed and detached from
React, and then the entire app gets destroyed and these errors get printed at
the error level, throwing some people off.

This was hit on a corner case when ConnectionService will deny
the request to start the call. I am not sure, but it could have been
that the conference object has been disposed or closed or something
else, but the fact is that 'conference.room' was not defined and things
crashed. It is not safe to access conference's private field 'room'. It
is true JitsiConference doesn't follow the practice of marking this
field as private with the underscore '_', but it is not a public field.

* Configurable (sub)optimal and unsupported browsers

* maybe this helps somehow

Also, use the helper function to get the display name for a participant.

* Updates kick showing who kicked us.

* Notify participants that someone was kicked.

* Shows notification to user who is remotely muted.

* Updates the notification type.

* Muted by notification for mobile.

* Moves code to react and adds the kick notifications to mobile.

* Updates lib-jitsi-meet.

The welcomePageEnabled and pictureInPictureEnabled props on mobile have been
converted to feature flags.

If a value is not set in localStorage then null is
returned. null should not be converted to an empty
string (via _.escape) because that will then be
stored in localStorage as the user set preference
and will keep overriding any other values set
in localStorage for the displayname.

- Use actions to notify the rest of the app that
  a mic or camera error has occurred
- Use middleware to respond to those notifications
  of errors by showing in-app notifications and
  notifying the external api

This PR changes the logic for connecting / disconnecting conferences. Instead of
doing it in mount / unmount events from the Conference component, it moves the
logic to the appNavigatee action.

This fixes a regression introduced in 774c5ecd when trying to make sure the
conference terminated event is always sent.

By moving the logic to appNavigate we no longer depend on side-effects for
connecting / disconnecting, and the code should be more maintainable moving
forward.

An improvement to this is the concept of sessions, which, while not tackled
here, was taken into consideration.

* Groups devices notifications by type audio/video.

* Fixes passing correct device array.

For the external api to fire update events out of the iframe, it
must first be initialized within the jitsi app. Any invocations
by the app to send updates events before initialization will
cause the api to swallow the events. The chosen fix is to
initialize the api earlier so the first update of app's redux
store fires update events that the api will also fire out of
the iframe.

This change will affect current behavior in that right now
the update event of the initial set of the avatar url is
blocked, but the change will make that event fire out of the
iframe.