[AKQAKIEV-41] Code refactoring. Added methods to controllers for loading entities without lazy fields
[AKQAKIEV-41] Added Logic for DB changes from server to GcmNotificationHandler.
Renamed entities. Code refactoring.
Added unregistration to GcmClient.
Updated ConfererWebClient due to adding new methods that returns entity json without lazy fields on server
Merge branch 'develop' of https://github.com/biellou/Conferer into nickolay-polozov

Conflicts:
	client/android/AKQAConferer/src/com/akqa/kiev/android/conferer/db/ConfererDatabase.java
	client/android/AKQAConferer/src/com/akqa/kiev/android/conferer/fragments/ConferenceListArrayAdapter.java
	client/android/AKQAConferer/src/com/akqa/kiev/android/conferer/fragments/SessionDetailsFragment.java