Add some high level bindings
Merge pull request #23 from sonwow/hl-bindings

Add some high level bindings
Merge pull request #22 from aydinkim/master

fix servo #472
Delete unused variable.
Enable debugging output.
Add dependencies on layers and opengles.
Implement TextureManager.
Remove spurious debugging.
Initialize GL context with a size.
Remove unused import.
Remove unneeded to_unsafe_ptr()s.
Remove skia debugging.
Merge pull request #24 from metajack/gpu-rendering

Gpu rendering
Remove Mac ifdefs now that Skia has linux support.
Merge pull request #26 from metajack/linux-gpu

Enable Skia GL on all platforms
Free context when draw target is freed.
Don't create extra reference to GL context on new.
Merge pull request #27 from metajack/mem-leak

Fix GL context leak.
Fix debug and release compiles.
Merge pull request #28 from metajack/debug-fixes

Fix debug and release compiles.