Change the way how precompiled tar ball is copied to /afs/cern.ch/cms/ge...

Scripts to create precompiled powheg tar ball. After running the script, the powheg tar ball is put in a local working directory. Then, the tar ball must be copied by the MC contacts (by hand) to the afs directory:
/afs/cern.ch/cms/generators/www/<scram_arch_version>/<beamenergy>TeV/powheg