Several scripts and modifications to get the spin analysis fit for the legacy paper

First commit was closed as had merge conflicts after modifications made in pull: https://github.com/h2gglobe/h2gglobe/pull/407 

This commit is identical but merges successfully. Changes:

These include modifications to allow for parametric signal model fitting with the spin
	- spin analysis datafiles with systematics
	- SimultaneousSignalFitting classes and script for running spin parametric model
	- change to datacard maker such that spin card can be made with this script too

And also mods for running spin stuff in combine
	- can make channel compatibilty plot with profiled but unique mass in each channel
	- can run seperation jobs standalone and using the grid