Changes

Implement Voice Resume (#410)
* First attempts on working voice resume logic
* Added handling for HELLO
* Removed unneeded field, properly replace audio manager references on
reconnect
* Fixed a race condition on reconnecting audio connections after
invalidation process
* Fixed synchronization deadlock issue for AudioManagerImpl cache
* Added log for decoder errors
* Fixed NPE in decrypting audio packet
* Move warning for USER_SPEAKING_UPDATE on AudioConnection.LOG and put
it on trace temporarily
 (commit: 6c7e405)