Update ignores for new bindings path.
Fix makefile targets.
Fix dependencies.
Get rid of initial reshape.
Switch to GPU rendering.

This uses shared GL contexts and FBO rendered textures.
Update submodules.
auto merge of #518 : metajack/servo/gpu-rendering, r=pcwalton

This uses Skia GL to render to offscreen FBOs and then passes the resulting textures directly to the compositor.

It depends on https://github.com/mozilla-servo/rust-azure/pull/26 and https://github.com/mozilla-servo/skia/pull/14

r? @pcwalton