MOSYNC-3122. Changed camera demo alert strings and made small fix to antroid camera runtime.
MOSYNC-3122. Fixed image button bug on wp image button that was related to camera demo.
Merge pull request #428 from mvasiliniuc/master_CameraFixes

MoCamera "Hanging - Snapshot failed" related fixes
MOSYNC-3019: small code refactoring + documentation + threading corner case covered; MOSYNC-3019: implemented the basic structure for immediate error checking + implementations for: WidgetBaseWindowsPhone, Screen, TabScreen and StackScreen
Merge origin/master conflicts solved