Common Isolation & Selection Frameworks 72X Edition

#4685 + Code review comments and improvement of user interface.
Update of TWiki to come soon.

Also integrates code into MiniAOD, right now only electron IDs are embedded.

No ID code is run in the standard reconstruction at present.
We will need to talk to Validation/DQM about how to port the IDs that are used there into the framework.

Backports: 71X - #5015, 70X - #5014

@ikrav @Sam-Harper @arizzi
The if block is basically repeated again for PAT. I'd suggest making a template along these lines: http://cmslxr.fnal.gov/lxr/source/CalibTracker/SiStripCommon/plugins/ShallowTree.cc?v=CMSSW_7_2_0_pre4#018 
Later the loop could be (I think) with for(const auto &iEle : src){..}. 
Any reason all this would not work?