Add KeepGlobalAudioAlive to prevent freeswitch from kicking out global audio from voice conference. The time from sending the keepAlive is in milliseconds and is inside KeepGlobalAudioAlive.java
Merge branch 'global-audio' of git://github.com/mconf/bigbluebutton into global-audio
Fixed error in field.
Merge branch 'global-audio' into mconf-live0.3