New live ebuild for VGM and Geant-VMC

Geant-VMC switched to cmake, future releases will support cmake only => new ebuild. 

I have asked upstream to fix their installation paths for both VGM and geant-vmc, they did this in trunk, so we can drop the manual installation in the live ebuilds already. 
I will skip geant-vmc-3.00.b01 from packaging, it does not yet have those fixes (and also other cmake-related issues), a new release should happen soon. 

VGM-4.00 is released, but: 
1) without those fixes. 
2) upstream again only provided an SVN tag, no tarball. 
I am discussing with upstream whether they can please provide tarballs in the future, and will then bump vgm-3.06 to vgm-4.00 as soon as this has happened (or ask for mirroring here again).