Merge pull request #10 from pcwalton/language-changes

Update for language changes
Merge pull request #11 from pcwalton/container-layer-fix

Fix bug whereby container layers were not setting transforms on their children
Merge pull request #12 from eschweic/master

Better Zooming
Add texture layer support.
Merge pull request #13 from metajack/gpu-rendering

Add texture layer support.
Add remove_child() to ContainerLayer