Removing GameCenter dependencies in the core:

OKScoreProtocol and OKGKScoreWrapper are not longer needed.
Removing GameCenter dependencies in GUI.
Just cosmetic changes, making openkit's base code consistent.
BIG REFACTORING. Part 1

- New modular system for login
- New user management
- Security improvements
- Cosmetic changes
- New score submitting system
- New Xcode project to test the core
- UI and logic are not longer together

IMPORTANT: UI is broken at this point
Merge branch 'newLogin' into manuBranch