- [OBMFULL-4801] Backends are not part of ObmSyncModule
- [OBMFULL-4801] Bind EventService with mocks control
- [OBMFULL-4801] Windowing key in calendar and contacts backend must be sync key

Conflicts:
	java/sync/integration-testing/src/test/java/org/obm/opush/MailBackendHandlerTest.java
	java/sync/opush/push-module/src/main/java/org/obm/push/handler/BackendWindowingServiceImpl.java
	java/sync/opush/push-module/src/main/java/org/obm/push/handler/GetItemEstimateHandler.java
	java/sync/opush/push-module/src/main/java/org/obm/push/handler/ResponseWindowingService.java
	java/sync/opush/push-module/src/test/java/org/obm/push/handler/BackendWindowingServiceImplTest.java
	java/sync/opush/push-module/src/test/java/org/obm/push/handler/ResponseWindowingTest.java