WCSim Validation

0741c96eae9e4dba2a249e813c78186d10e3908f

Pull Request #560: Standardise sampling method for li sources

SK_500MeVem_centre_xdir

Tests
3000.74 sec
wcsimrootevent plot pass
wcsimrootevent2 plot pass
wcsimrootevent_OD plot pass
Geom pass
bad pass
Geometry warnings pass