WCSim Validation

4faa39058cd6a7574949b17c0664a048ec3aaeb4

Pull Request #557: Feature/individual pmt dark rate

SK_500MeVem_centre_xdir

Tests
3306.13 sec
wcsimrootevent plot pass
wcsimrootevent2 plot pass
wcsimrootevent_OD plot pass
Geom pass
bad pass
Geometry warnings pass