Add a new plugin mechanism for extender G4Shapes such as the LArWheelSolid....
Add a new plugin mechanism for extender G4Shapes such as the LArWheelSolid. Remove the code for the LArWheelSolid from the GeoModel repository. It now lives as a plugin in the GeoModelATLAS repository.
In addition:
- configured gmex to look for geometry plugins where they are installed.
- configured geo2g4 to look for shape plugins where they are installed.
- configured fullsimlight and gmgeantino to look for data files where they are installed....
- ... IF the geant environment is not set up. (otherwise take the geant environment)