[Halla12_software] test SoLID simulation with GEMC 2

[Zhiwen Zhao]

Dear All

In an attempt to move SoLID simulation from GEMC 1 to GEMC 2, we have 
converted all solid CLEO geometry files and put them into SVN at a 
temporary dir called "solid_gemc2"
One major change is that the geometry is stored in text files instead of 
mysql database, see file "solid_gemc2/changelog" for details

Here is a temporary wiki page covering GEMC 2 and solid_gemc 
installation and how to run the simulation.
https://hallaweb.jlab.org/wiki/index.php/Solid_Software

The todo list includes
1. materials in external files
2. detailed detector simulation
3. add hit process routing
4. ...

As this is a test release, there will be changes made often on both SVN 
and wiki.
Please use a graphic SVN client so you can see update automatically.

Please note GEMC 2 is currently at devel stage, but we will release the 
formal version very soon.

Let me know any question and comment.

Thanks

Zhiwen