Updates to MuonEfficiencies in 2012

Added in the MuonEfficiency root files for Run2012 (one file for ID and Iso for the full dataset, 3 for trigger corresponding to runs AB,C and D)

Modifyed TagAndProbe/python/MuonPOGCorrections.py accordingly:
a) new functions, keeping the old versions in case somebody wants to double check / not harm their analysis 
b) updated the function to understand division in barrel-overlap-endcap

This fixes the data/mc disagreements observed with the SingleMuon dataset. 

It could potentially be beneficial for any muon analysis using UWHiggs as well (since I updated the isolation and ID corrections)