WCSim Validation

6519803d54a12cb4b108c40bf878d19c9a3037bb

Pull Request #571: Use cm for photon start & end times from photons, to be consistent wi…

WCTE_500MeVem_centre_xdir

Tests
2143.37 sec
wcsimrootevent plot pass
wcsimrootevent2 plot pass
wcsimrootevent_OD plot pass
Geom pass
bad pass
Geometry warnings pass