added systematics
misc updates (something is funny with the systematics, fit doesn't change when they are added)
hacks to try to get this working through histfitter. We've left the realm of science, but maybe magic will save us
got systematics working (I think)
commenting, cleanup, and docs
docs
add option to dump a histfitter workspace and then quit
add multiple configuration support
bugfix
add combination for b-tagging systematics
some restructuring
various fitter fixes
add support for relative systematics
add warning (and dummy value) when systematic yields aren't found
added combined tagging option to fit configuratino
allow for missing backgrounds in input files (just sets the value to zero)
add  directory from the HistFitter package
change scripts over to using local HistFitter stuff
the 'afterFit' workspaces and '_upperlimits' files are produced when susy-fit-workspaces.py is run with '-m'
Update README.md