Minor changes.
setSkin with no previous skin attaches setup pose attachments.

No more API gotcha, setSlotsToSetupPose is not needed.
License header update.

2 -> 2.1 (clearer how permission is granted, formatting).
Support attachment loader discarding attachment by returning null.
Formatting.
Fixed mesh hull debug rendering.
Throw exception if a mesh can't be rendered.
Merge branch 'officialmaster' into unity-ffd