ServerMethods: Fix error message when suscription parameter is missing

Change-Id: I876c93d728617a09868bd75abc4750f8bee17630
MediaSet: Implement session autorelease

If no keep alive is received or no elements on the session is
being used in a callback for a time, a session will be released

Change-Id: Icbdc6c7d21d47190d73dff0845f311b5ed62e19d
MediaSet: Remove unused exception

We are using KurentoException

Change-Id: Ie1551e41e970b800ba01c7994fb7e56100e42c12
MediaSet: Improve logs

Change-Id: Ia1d2556262278c94389f25420d9c5b1506e085ea
MediaSet: Use monitor instead of locks

Change-Id: I066b2c90285130ff436475fb69674364a5351815
Use MediaSet to get and reference objects automatically

Change-Id: I6c8975af37537801a06cc10466825c0b0da3448b
Unify exception management on RpcHandler

Change-Id: I6ce27d5be4c01d56604d14b284256f7a2f8d0bbe
Improve objects release at server shutdown

Change-Id: Ic9d6029642e9f198ba62d87fb7b9f10f622c0c97