Update ImageLoader.hx

Added support for "crossOrigin" image requests which do not taint canvas's.  

Further info @ http://blog.chromium.org/2011/07/using-cross-domain-images-in-webgl-and.html
Merge pull request #9 from Richard-Walton/master

Set `image.crossOrigin = "Anonymous"` in JS ImageLoader to allow use of bitmaps loaded cross origin without "tainting" canvas in current security sandbox.