(cherry picked from commit 9389ecac)

# Conflicts:
#	CMakeLists.txt

(cherry picked from commit 7cd04def)

- Building the internal qhull version fails on Ubuntu18.04
- Therefore, the included qhull version is removed

rbdl wrapper supports now multiple bodies between joints (inertina combination is untested; uses rbdl code to combine

This allows to identify the triangles which caused the collision

MJCF library, MujocoIO and Simox2Mjcf utility

See merge request Simox/simox!34

# Conflicts:
#	VirtualRobot/XML/mjcf/MujocoIO.cpp
#	VirtualRobot/XML/mujoco/MujocoIO.h