system.js - base64 rotate image case

sorry for the wrong branch
Merge pull request #95 from blaspix/patch-11

Added Data URI support to rotate image
Small debugDraw fixes
Updated debugDraw syntax
Fixed Animation parameter
Fixed code style
Fixed Loader to skip already loaded files
Fixed playMusic to change currentMusic, when music is muted
Added onComplete method to Loader
Added string shorthand to Tween easing
Tweaked SceneGame example
Added center method to Sprite
Updated SceneGame
Doc update
Changed speed property type to Point on TilingSprite
Moved PIXI into own module
Fixed center method to return this on Sprite
Optimized core code
Changed startScene lookup order
Optimized example scene