Protections against high pT pions becoming tracker-driven only gedGsfElectrons

Tested in: CMSSW_7_0_X_2014-02-02-1400

Part 2 of splitting up #2241. Comes after #2242.

This pull request contains an update to gedGsfElectron producer to harmonize the pre-selection of tracker-driven-only gedGsfElectrons above 50 GeV as well as an update to the pre-selection MVA (as in #2241).

See old PR for plots.

This contains updates for high pT tracker-driven-only electron protections against pions.