Add support for compat versions to add_maven_depmap
    
    -v argument makes it possible to create compatibility versions for
     muliple artifacts that share gid:aid but are incompatible between
     versions.
    
    Compat jar needs to be placed in the same place as orginal in
    %install section. -v switch will then make sure to move this file to a
    versioned location and add additional symlinks if necessary.