[Hallcsw] Update to SIMC

[Mark Jones]

The SHMS section of SIMC has been updated.
The changes are described at
https://hallcweb.jlab.org/wiki/index.php/History_of_SIMC_CVS#Mar_14__2012

If you have checked out the CVS version you can do a cvs update.

Instructions for checking out the code are at
https://hallcweb.jlab.org/wiki/index.php/SIMC_Monte_Carlo

One point is that by default the 1st cerenkov before the
wire chambers is in the detector stack for multiple
scattering by default.
If you want to remove the cerenkov
and have a helium bag then in  shms/mc_shms_hut.f set

parameter (cer_flag = .false.)


           Cheers,
                  Mark