Updates to the NpolEventAction and NpolSenstiveDetector files to include energy cuts on the detectors taking "hits" during the event.  This is a first past attempt at identifying (n,p) events from energy-tracking information.

Also updated the npol.mac file so the initial energy of the neutron is 2500 MeV.  The lowest energy neutron in the proposal is 2110 MeV.  This is a new base line.