MG LO GP python2 fix
Restores python2 compatibility for MG5_aMC 2.9.3+. No longer use "bin/run.sh" wrapper script (which calls ./bin/gridrun) but directly use "python bin/gridrun" and perform environment setup and moving of events in python.
Restores python2 compatibility for MG5_aMC 2.9.3+. No longer use "bin/run.sh" wrapper script (which calls ./bin/gridrun) but directly use "python bin/gridrun" and perform environment setup and moving of events in python.