Use GetPosition2D() when appropriate.
Simplified lua samples 08_Decals and TestScene
Remove pushFront argument from Node::GetOrCreateComponent, fix issue #579, because it is important than issue #569, I think this function can rename to Node::RequireComponent.
Travis CI: API documentation update at 2014-12-27 13:51:48 UTC.
[ci package]
For Travis CI - switch CI build to use OS X build environment.