modifing EgammaHLTGsfTrackVarProducer to produce 1/E-1/p as well

This is a modification to the producer that makes the HLT Gsf track related variables to also make 1/E - 1/p. The timing should be negligible and it has run on ~100K Z'->ee events without crashing. This is a necessary addition for the E/g HLT. Speaking as E/g Reco & HLT subconvenor, I would like this change to go in the next available open pre-release. Many Thanks!