EGM - PFPhoton Selection / Particle Based Isolation / New Soft-Electron ID / New Converted Brem Finder / ECAL Regressions for PF-SCs+Electrons+Photons

built on top of CMSSW_7_0_0_pre10

This is the last major update to the EGM software for 700 with the aim of bringing it to an 'analysis ready' state for the HPA exercise in 2014.

You will need to manually download the new MVA weight file, for the classifiers, in the following packages:
RecoParticleFlow/PFTracking
RecoEgamma/ElectronIdentification

with the usual ```cat download.url | xargs wget```

Changes can occur in:
- PFBlocks, due to the brem finder and changes to photon importing requirements
- electron efficiency and fake rates, from the new electron ID and corresponding preselection of tracker-driven electrons
- particle based isolation for gedGsfElectrons and gedPhotons (these are a value map in the event, we'll post the plots for you)
- Improved energy resolution for Mustache-SCs and for gedGsfElectrons & gedPhotons p4, from the regressions. 
   - There can also be changes to the energy resolution for electrons from the new converted brem finder.

The PR for setting the GED RECO to default will come on another PR, based on top of this one.

There will be a follow up after this PR is merged for the GT update in #1835. 
This will just be removing the ESPrefer statements for the PF-SCs, electrons and photons.