MKFacebook Changes

• -(void)setUseStandardDefaultsSessionStorage:(BOOL)aBool; added
• -(BOOL)useStandardDefaultsSessionStorage; added
• -(BOOL)hasPersistentSession; added
• -(NSDictionary *)savePersistentSession; added
• -(BOOL)restorePersistentSession:(NSDictionary *)persistentSession; added

- fixed NSString append nil issue. Thanks Andrei Freeman.
- new login window looks a little like the iPhoto '09 login window