Voice.cs: added more commands
Supported commands as of this commit: open, play, pause, rewind, stop,
mute, unmute, increase volume, volume up, decrease volume, volume down,
next chapter, skip chapter, previous chapter, next, next file, previous,
previous file, fullscreen, view fullscreen, go fullscreen, exit
fullscreen, leave fullscreen, hide, show, whats playing, help, stop
listening, close