implemented some functions into AppFacade
fixed score = null bug in RegisterActivity
Merge pull request #44 from XiDevelopment/AppFacade

Functions in AppFacade; score bug fixed
Updated Social Tab.
Friend requests are now displayed, and can be accepted or declined.

Every interaction with AppFacade now runs via a AsyncTask.
Merge pull request #45 from XiDevelopment/social-tab

Social tab