Merge changes I1b1abc2c,I47083821,Icbe72d36,I6292beb0,I14b750ac, ... into devel/master

* changes:
  Test harness sync
  Limited joint/weight attributes to 4 sets
  Added vertex color test to model primitive
  Add macro defs to shader regen
  Adding debug to shader defs
  Updated model loader to handle multiple attr sets
  Switched joints to use UBO with larger size in PBR shader