Added getLocalBounds function to displayObject

added a constant identitiy matrix constant to PIXI
Merge branch 'dev' of https://github.com/GoodBoyDigital/pixi.js into dev
Added tint to Sprite test
Small bit of code file organisation for webGL renderer

also tidied up the grunt file to reflect changes to folder structure
Fixed stage ref bug
map file no longer used
Fixed bug where setText not working correctly

Docs updated
Added removeStageReference fix
Tiling Texture fixed to allow any size texture

also accepts sprite sheet frame.
Fixed bug with interaction when setting internal stage reference
Added Tinting and BlendMode example
Fixed issue with setStageRefference and worldVisible function
Added setStageReference to DisplayObject

Removed unused reference to PIXI.gl (no longer used)
Fixed webGL destroyTexture function

added PIXI.glContexts to access to contexts when destroying textures
removed constant PIXI._defualtFrame as its no longer used
Removed unused variable PIXI.WebGLRenderer.gl
removed a few more unused variables

replaced [] with .length = 0; to reset arrays
ENV variables specific to this fork
Added instrumentation, coverage, and coveralls support

The previous is separated out as an example to add coveralls support.