Merge pull request #1 from denis-minchuk/master

box2d changes and box2dtests added
don't reload raw assets
Merge branch 'master' of https://github.com/Cocos2DXNA/cocos2d-xna
Merge pull request #2 from denis-minchuk/master

reordered tests
separation Draw and Step
Merge branch 'master' of https://github.com/gena-m/cocos2d-xna
removed c++ formats