TilingSprite fixes

Fixing issues #376 and #371.

Resize bug was due to vertex buffer not being updated. 

The other bug was introduced with the new changes to shaders (push/pop). I included a quick fix but it will likely change again with the fixes mentioned in #375.

Now that the build is only three files, I feel like it isn't such a bad idea to include it in PRs and commits. This way when people checkout the dev branch, the examples work out of the box. Let me know your thoughts on this..

Also I strongly feel that TilingSprite should be reworked like so:

- It should extend Sprite, as the name implies.
- It should not rely on a separate batch or shader. It is really just a sprite (two triangles) with different UVs, so it should be rendered together with other sprites to improve batching and reduce shader switches.
- Rendering is too tightly coupled with WebGLRenderGroup IMHO. I think it should be pulled out. However I think we would have to consider this further, and try to make keep things consistent when we implement filters, Graphics, and other "special" render objects.