WCSim Validation

5935d2f3309275a0f6801913a62ed8abfcf21240

Pull Request #541: fix tyvek modeling

SK_500MeVem_centre_xdir

Tests
3269.34 sec
wcsimrootevent plot pass
wcsimrootevent2 plot pass
wcsimrootevent_OD plot pass
Geom pass
bad pass
Geometry warnings pass