Added a bunch of features

Added ttbargencut, flavor selection, pileupfile, bjet systematics, JEC, JER, and PDF Systematics, and sample veto and filter. They 'should' all work, but check some of the xml configs before you submit them. I have checked that all the changes configure the xml config file as expected, but due to the huge number of combinations I haven't ran them all so pay attention and report bugs.