New live ebuild, using cmake-buildsystem (upstream switches to cmake for next release), add flags for g4root and mtroot. Adapt to upstream's fixes concerning install paths, we don't need to do manually installation anymore.
I will skip geant-vmc-3.00b01 from packaging, it does not include those fixes yet.
New live ebuild for VGM, adapting to fixes for cmake install paths in upstream (no need to manually install in ebuild anymore).
Released VGM-4.00 does not have these fixes yet, I am discussing with upstream whether they can also provide some tarballs of released versions (as sourceforge svn-snapshotting is unusable for us) and delay packaging of VGM-4.00 until then.
Add subslot dependency on clhep, we need to rebuild for each clhep subslot change.
Merge pull request #236 from olifre/master

New live ebuild for VGM and Geant-VMC