[TIMOB-1238] Android application lifecycle issues: app activity can be destroyed, but app still not terminated

Stems from http://developer.appcelerator.com/helpdesk/view/20811">http://developer.appcelerator.com/helpdesk/view/20811. In that case, user would back out of program and TiRootActivity's onDestroy would get called, but yet the Application would never terminate. (TiApplication.onTerminate never hit breakpoint). When user launched the application again, it was more like a resume, since it had never terminated. This meant that the same instance of TiApplication was being used, and singletons such as those maintained in TiModule's modules hashmap were still alive. This leads to weird stuff, since the application "kinda" terminated but didn't really.

To be very specific regarding that helpdesk issue: when user backed out of program, AppModule's onDestroy removed itself from TiApplication's appEventProxies collection. When the app started up again, the AppModule singleton was still alive, which means its constructor did not run again, which means it was never added back to the Application's appEventProxies collection. So no calls to Ti.App.fireEvent worked.