[Clas12_software] svn directories move

[Maurizio Ungaro]

In compliance with the new clas12 software directory structure I moved the projects below to the new location.
The projects have their release versions in a "tags" sub-directory.

gemc  
scons_scripts
scrat
banks

The build scripts will be modified to work with this new structure as soon as possible.

gemc_evio2root will not be moved as this project needs replacement.

Best,
Mauri