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)
Summary of changes:
1) Changed include paths to be relative to the current sources (affected
files: LoadMeshFromObj.cpp, Wavefront2GLInstanceGraphicsShape.h/cpp)
2) Added new tutorials in the ExtendedTutorials folder
3) Modified the main_opengl_single_example.cpp file to enable picking
support in standalone demos