Will also add Erin Catto's local implicit version from the GDC 2015 tutorial
Added demo for btGeneric6DofSpring2Constraint, thanks to Gabor Puhr
Add gfxBridge.autogenerateGraphicsObjects method for Bullet 2 demos in new framework (need to implement all Bullet 2 collision shape types...)
Use 1,1,1 for local scaling in btStaticPlaneShape
remove various vertex format structures and use GLInstanceVertex from #include "OpenGLWindow/GLInstanceGraphicsShape.h"
btMultiBody::setupPrismatic takes an additional argument to allow a shift of inertia tensor, relative to the joint frame (link frame at q=0)
Fix WinXP GetTickCount64 with a typedef
Expose debug drawing mode/flags in UI (hot keys A,D,L,W for now, buttons later)
GLInstancingRenderer: tweak near/far planes to allow closer approach of camera
btDiscreteDynamicsWorld: enable debug drawing for btGeneric6DofSpring2Constraint
btMultiBodyDynamicsWorld: enable basic debug drawing for btMultiBody
btMultibody: allow center-of-mass shift for prismatic and fixed constraint
add small experiments to distribute points on a sphere
prepare for coordinate frame demo (incomplete)
fix/hack around gwen update of scroll bars and Focu
