Fixed Loader to store all json data on game.json
Loader fires the completion code even if nothing was loaded
Merge pull request #102 from sandymacpherson/develop

Loader fires the completion code even if nothing was loaded
Added crop method to Sprite
Fixed crop to return this
Added SpriteSheet class
Optimized SpriteSheet code
Fixed audio support for iOS 6
Added detection for Android stock browser
Fixed device specific config
Fixed iPhone 4 detection
Fixed iOS innerheight bug
Fixed audio on IE11
Fixed audio loading when disabled
Fixed another iOS innerheight bug
Fixed audio issue on IE10
Fixed collide direction parameter on hitResponse
Changed collideAgainst type to array in Body
Fixed keysDown on window blur
Fixed Animation to use delta time