geometry utils impl separation r65
Extras circle geom r65
Tweaks to sync'ed euler/quaterion

Minor simplification for the synchronized Euler/Quaternion pairing.
Remove obsolete index0AttributeName
colors attribute fix
Add SDL_Init video/events and gl compatibility profile
Further index0AttributeName cleanup
continued work on extras/geometries + example
Merge branch 'dev_r65' into dev_r65_extras
ring geometry and circle impl in cpp
Extras polyhedron geometry
icosa and octahedron geometries and toArray instead of init lists