Mini aod from710pre5

MiniAOD implementation following the talk at
https://indico.cern.ch/event/293016/session/7/contribution/65
more info at:
https://twiki.cern.ch/twiki/bin/view/CMS/MiniAOD

70X branch:
https://github.com/arizzi/cmssw/tree/miniAOD-from700

@gpetruc @bendavid @arizzi