Modify PYTHONPATH on import of MadGraphUtils [AGENE-2049]
Modify PYTHONPATH when including MadGraphUtils so that both MadGraphUtils and MadGraph executables pick up a patched version of shutil. Remove old monkey patch.
Modify PYTHONPATH when including MadGraphUtils so that both MadGraphUtils and MadGraph executables pick up a patched version of shutil. Remove old monkey patch.