Initial setup to play audio across all Hangout member clients

This commit includes the basic setup for playing audio across all the clients participating in a google hangout.  It includes the following:
  - hangoutsmusicplayer.html
     * includes html elements for hangout app
     * includes javascript to execute the sound playing across all clients
     * includes configuration for sound execution
  - hangoutsmusicplayer.xml
     * includes the basic configuration for the hangout app
     * inclides a CDATA element where the HTML for the hangoutsmusicplayer.html goes