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.

According to Apple iOS devices with versions < 9.0 are 6%.
https://developer.apple.com/support/app-store/

Xcode insists on automatically fixing the project file with tvOS
support. In order to not have to constantly ignore these automatic
changes when committing, commit them.

Bundle our custom icon font jitsi.ttf in the Android app (which we
already do for the iOS app).

Additionally, remove icon font files which are not in use.

As a step toward merging jitsi-meet-react with jitsi-meet to share as
much source code as possible between mobile and Web, merge the part of
jitsi-meet-react's source tree which supports mobile inside the
jitsi-meet source tree and leave jitsi-meet-react's Web support in the
source code revision history but don't have it in master anymore because
it's different from jitsi-meet's Web support. In other words, the two
projects are mechanically merged at the file level and don't really
share source code between mobile and Web.