CC-5450 : Refactor Media Management (Classes/DB) in Airtime

working on jplayer
Merge branch '2.6.x' of github.com:sourcefabric/Airtime into 2.6.x
Merge branch '2.6.x' of github.com:sourcefabric/Airtime into 2.6.x

Conflicts:
	airtime_mvc/application/models/airtime/AudioFile.php