Make btQuickprof thread safe
Add option in btQuickprof to override custom timing profile (btSetCustomEnterProfileZoneFunc, btSetCustomLeaveProfileZoneFunc)
remove b3Printf in a user/physics thread (those added added, while drawing the GUI running in the main thread)
add test for VR HUD/sub-titles
fix issue in previous commit, partial string use %.8s not %8.s
use long long int in b3Clock
fix warning/error in pointer alignment in serialization
Fix pybullet Windows compilation.
(thanks to bkeys/https://github.com/bulletphysics/bullet3/pull/687)