enable running on MiniAOD, switch to new JetCorrector

We integrated the new JetCorrector into the Jet Validation. In addition we rewrote parts of the code to enable running on MiniAOD both for the Jet and MET Validation packages. The python files have been modified to include an additonal MiniAOD sequence. We tested the code on RECO and MiniAOD 720pre8 relval ttbar 25ns datasets.