Trigger workflow

Some trigger work in progress.
So far:
- added the module to store the trigger objects of interest (off by default)
- removed '2012' from unfolding selection naming as its applied to both 7 and 8 TeV samples
- added the flag for modified (tag and probe) selection to drop dilepton veto

To do:
- add the Z mass window cut for 2 leptons
- increase the list of trigger objects of interest, map to corresponding run numbers and HLT paths