Fixed TilingSprite not render children on canvas

TilingSprite does not render children on 2d canvas. The call to
children's renderCanvas method is missing.
Fix Text.destroy() and fix memory leak in BaseTexture.destroy() if basetexture was from canvas
Implemented animationSpeed for Spine animations.
Default value is 1.
This is simply the "timeScale" value from the Spine runtime, but with a more friendly name.
added width and height properties to displayObject

Also anded render back into text example
Merge pull request #647 from giraluna/destroy

Fix Text.destroy() and memory leak in BaseTexture.destroy()
Merge pull request #659 from ryanmcnz/dev

Implemented animationSpeed for Spine animations.
If the texture is destroyed, it should be removed from TextureCache too
Some browsers return null instead of throwing Exceptions
Merge pull request #738 from panrafal/fix/destroy-texture

If the texture is destroyed, it should be removed from TextureCache too
Fixed filter bug

fixes issue where if both mask and filter are applied to one object the
object did not render.
Merge branch 'dev' of https://github.com/GoodBoyDigital/pixi.js into dev
Merge pull request #599 from glassesmouse/dev

Fixed TilingSprite not render children on canvas
Added an error event dispatch when an image cannot be loaded.
syntactic sugar
Forgot a space to match code style.
Merge pull request #739 from panrafal/fix/webgl-create

Some browsers return null instead of throwing Exceptions when creating webgl
Don't blame me ;)
Merge pull request #743 from panrafal/fix/webgl-create

Small bug when creating webgl prevents some browsers from working
Fixed RenderTexture.resize so it now works across WebGL and Canvas. Uses the textureBuffer to resize and has a new optional 'updateBase' parameter which will set the new dimensions on the baseTexture as well. Fixes #746.
Added RenderTexture.clear - because, well, it's really useful :)