High pu mc branch 625

I discovered that the 5GeV cut made things worse.  Since a supercluster can have a seed cluster of 1GeV or greater, I ended up causing many more events to fail when the supercluster tried to access its seed cluster.  But the threshold for seed cluster is 1GeV for both EB and EE superclustering algorithms.  So, this cuts most of the basic clusters from pileup, while preserving all seed clusters for the superclusters.