[Android] [URBNG-274] Add logout functionality
Changed that "Logout" menu item is not visible if user is not logged.
Merge branch 'android' of github.com:lucdom/UrbanGame into android_URBNG-360

Conflicts:
	UrbanGame/AndroidManifest.xml
	UrbanGame/src/com/blstream/urbangame/LoggingInActivity.java
	UrbanGame/src/com/blstream/urbangame/MainActivity.java
[URBNG-360] Added GsonTaskAdapter class to commit
[URBNG-360] Made suggested changes
Merge remote-tracking branch 'remotes/blstream.origin/android' into android_URBNG-360
[URBNG-360] Added enum and default case statements.
Merge pull request #60 from lucdom/android

[Android] [URBNG-360]