Redesign of the mirror holders
	Replace old MirrorSupportBelts by new MirrorFixing which looks like the CAD model and the prototype
Add a small plate at end of mirror support studs to fit the weight
Fixing all overlaps in the geometry
Fixing newly discovered bug in implementation of exit window
	change of geometry hierarchy at exit window
	similar change at entrance window to avoid potential of similar bug
Additionally small changes (small regarding physics impact)
	changes in the volume hierarchy to reduce the depth
	changes in code of creator file to make it more efficient
	replacing some hard coded numbers by variables
	replacing double definitions of same volumes by copying