[Clas12_software] gemc update

[Maurizio Ungaro]

I'm currently investigating a problem with the geant4 9.6 magnetic fields. Geant4 9.5 works normally.
Until this is resolved, I advice you use geant4 9.5. You can do it by setting these lines before sourcing jlab.csh on your login shell script:

setenv GEANT4_VERSION 4.9.5.p01
setenv CLHEP_VERSION 2.1.2.0
setenv QT_VERSION 4.8.1
setenv GEMC_VERSION 1.p8

(you need to set the other versions as well for the dependencies).

Also: I'm working on gemc 2.0. It includes several improvements, additions and bug fixes.
gemc 2.0 is a partial clean up and rewrite of the code in a better object oriented fashion. 

I expect gemc 2.0 to be ready late February.

Cheers,
Maurizio