[Halla12_software] -USE_PHYSICSL=gemc and "envelope volume" overlap

[Zhiwen Zhao]

hi, folks

two things.

The default physics list of gemc is not setup as "gemc" and it has to 
setup explicitly with -USE_PHYSICSL=gemc.
refer to
https://hallaweb.jlab.org/wiki/index.php/Solid_run

For previous solid geometry, I have done them in a "envelope volume" 
way. Now I have removed the "envelope volume" to avoid volume overlap.
refer to
https://hallaweb.jlab.org/wiki/index.php/Solid_geo#geometry
geometry files for BaBar_SIDIS are updated in svn. others will be 
updated later.

cheers.

Zhiwen