Code update and maintenance to increase granularity in resolution studies

• genBinsFine binning scheme removed (from $DAS_SOFTWARE/Core/JEC/bin/common.h). Replaced with an updated version (in $DAS_SOFTWARE/Core/CommonTools/interface/variables.h) of pt_edges.
• Replaced variable genBins with variable edges for the function FitResolution inside $DAS_SOFTWARE/Core/JEC/bin/fitJERcurves.cc .
• Removed "MC" from the name of the 3D histos used for the resolution. ($DAS_SOFTWARE/Core/JEC/bin/getJERcurves.h)
• There is no resolution response with respect to ptrec anymore, but there are two 3D histos, one to fill with ptgen and one to fill with ptrec ($DAS_SOFTWARE/Core/JEC/bin/getJERcurves.h)
• Trying to compare results between filling the 3D histos used for the resolution with the (pure) rec level weight only and with gen times rec level weight ($DAS_SOFTWARE/Core/JEC/bin/getJERcurves.h)