Merge remote-tracking branch 'refs/remotes/github/dev' into dev
remove test of _enabled because it should now be done before calling DrawCall.apply()
use string literals for texture formats to avoid compatibility issues
refactor imports
add numEnabledDrawCalls, numDrawCalls and numEnabledPasses properties
Merge remote branch 'origin/dev' into dev

Conflicts:
	src/aerys/minko/scene/controller/scene/RenderingController.as
fix duplicate function definition for Scene.numDrawCalls getter