Cherry-picked from !2375 (merged) on
Modify SimConf.py to take into account that if PGPrimaryVertex is run, it needs to write the "reconstructed" PV at the same time.
- add PGUN to simconf to write faked PV to dst
addMCVerticesto ask if PGUN is set. If so, write to 'Rec/Vertex/Primary'
Will need to be ported to all branches that contain Boole/Moore/Brunel/Stripping processing steps for all years of pGun productions with Gauss v54r0 (Sim10) and Gauss v49r16 (Sim09) or later. To be activated for steps that process pGun, by setting
Ready for merging, has been tested in