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
Removed this.worldVisible = true; line in PIXI.Stage fixes #477
Remove redundant code, fix trimmed sprite sheets
Merge pull request #478 from Nibbler999/dev

Remove redundant code, fix trimmed sprite sheets
Added cacheAsBitmap to PIXI.Graphics

Tweaked webGL graphics
Added generateTexture function to PIXI.Graphics
Merge branch 'DisplayObject-Cache' into dev

Conflicts:
	bin/pixi.js
tiny tweaks - removed replaced [] with length=0 in PIXI.destroyTexture
Merge branch 'dev' of https://github.com/GoodBoyDigital/pixi.js into dev
Merge branch 'dev' of https://github.com/GoodBoyDigital/pixi.js into dev
Fixed final ie11 webGL masking issue

removed IE11 check in auto detect function
Added AlphaMaskFilter
Update README.md
CocoonJS compatibility
Merge pull request #480 from ekelokorpi/dev

CocoonJS compatibility
CocoonJS fix on updateText
Merge pull request #481 from ekelokorpi/dev

CocoonJS fix on updateText
Merge branch 'dev'

Conflicts:
	bin/pixi.dev.js
	bin/pixi.js