Add status announcement via '*' menu

[mrscotty]

When caller presses '*1' (for example), play back audio for the following status information:

• Number of active channel users (not deaf, not mute?)
• Self-mute status (e.g.: "you are (not) muted")
• Remote-mute status (e.g.: "you have been remotely muted")
• Priority speaker?

Note: This requires a new class for tracking the user state messages from mumble. Also, the sound clips need to be pre-generated.