1. Add game center function in iOS.
2. Test OK for game center.
3. Add controller for game center in iOS.
4. Add new abstract class for game center.
5. Add new abstract class for community.
refactoring some code.
1. Add Facebook function.
2. Testing Facebook function.
1. initial permission for Facebook
1. Add community manager.

2. modify game center
1. Refactoring game center manager
2. Refactoring Community Exhibitor function.
1. Implement Facebook function in Android.
2. Implement feed function in iOS/Android.
1. Add initial check in android fb manager.
2. Add setting in mk file.
1. Implement Facebook function in Android.
2. Testing done in Android.