Update for Cocos2D, iOS 7 and fix some GL bugs.

[UPDATED]   Cocos2D to release-2.1.
[FIXED]     Some GL state bugs.
[UPDATED]   Using VAO for holes, stars and buildings.
[IMPROVED]  Only update GL state on draw to avoid unnecessary updates.
[UPDATED]   malloc -> calloc in preparation of ARC.
[UPDATED]   Project configuration for iOS 7.