Merge pull request #996 from agamemnus/patch-5 ...

Reduce some logic redundancy in clearRect/fillRect code for Canvas...?

added custom shader

Fixed Strip Alpha bug

CanvasRenderer Clean up

removed the renderStrip function from CanvasRender

canvas buffer removed from canvas renderer class

Separated out the canvas buffer class

Merge branch 'dev-filters' into dev ...

Conflicts:
	src/pixi/textures/RenderTexture.js

Fixed Graphics getBounds

js linted

Updated Graphics

removed texture check from render loop ...

saved on if statement! better than none :)

Update WebGLRenderer.js

Fixed pivot issue

Little blendMode tweak

Created new initContext function for webGLRenderer ...

less code = good :)

Removed update and destroy webGL functions

Removed PIXI.texturesToUpdate ...

No longer required

Removed the updateFrames global Array

Rewrote update transform ...

matrix now used correctly.

merge in some doc fixes (#967)

merge bubbling events (#914)

Update CanvasRenderer.js

Merge pull request #946 from DuskEagle/dev ...

Fix WebGlContextLost handling.

Update CanvasRenderer.js

Reduce some logic redundancy in clearRect/fillRect code for Canvas...? ...

Topic.

Add clearBeforeRender for <webgl> ...

Maybe "clearBeforeRender" this is not the best naming (since it will clear anyway..), but this aligns canvas and webgl:

Basically it allows the user to do clearColor whenever they want, instead of this being done for them. This is useful in the following circumstance:

1) The game/program loads a background image, but not right away.
2) Before the background image is loaded, we want to fill the canvas with a certain color (for example, white).
3) In canvas mode, this is done by setting ``clearBeforeRender`` to false and then adding a single ``fillRect`` command.
4) In webGL mode, the equivalent is running ``gl.clearColor`` and then ``gl.clear``.
5) We can of course set the background color in webGL mode and this probably won't be expensive (although I don't know), but in canvas it *is* expensive to clear/fill on every frame.
6) Thus, the user would have to detect webGL mode or canvas mode themselves, and either set the background color or not.
7) To eliminate this coding complexity for the user, this small bit of extra code aligns ``clearBeforeRender`` (or, as much as possible) to the canvas implementation.

Merge pull request #994 from agamemnus/patch-2 ...

Fix for overwriting falsy values.. or even (possibly) undefined ones. (f...

Update WebGLRenderer.js

Update WebGLRenderer.js