Ensure popped scenes directly or via transition will resume.
Merge branch 'develop-v3' of https://github.com/cocos2d/cocos2d-iphone into develop-v3
issue #632 : 2x scale on not full screen mode in Mac-retina graphics
Applying jtwigg's fix for pin joints.
Merge pull request #617 from cocojoe/develop-v3

Ensure pushed scenes directly or via transition will resume with pop correctly.
Merge pull request #621 from DigitalRuby/develop-v3

Fix for swapBuffers crash and animations issue
Merge pull request #633 from krazyeom/issue-632

issue #632 : 2x scale on not full screen mode in Mac-retina graphics
Merge branch 'develop-v3' of https://github.com/cocos2d/cocos2d-iphone into develop-v3
Big performance improvement for bitmap font label