Sig syst

Hello Ted,

This branch implements the capability of reading the signal systematic uncertainties from a root file.  The root file is assumed to be present in the ra1e directory corresponding to the signal efficiency one is running over.

The major change is the fact that effUncRel needs to be defined per category.  To accommodate this, workspace had to modified.  
  
I've implemented a switch in configuration/signal.py to keep things backwards compatible. 

Y. 

ps. Forgot to mention my validation :

I ran once with a flat syst. uncertainty of 20%. Then I made a bogus root file with 20% uncertainty values in each bin and turned on the switch. The two matched. 

pps. 

The efficiency binning and the systematics binning don't match in Z (one is TH3D, the other TH2D) I've commented out the binning check for the systematics histo for now, but I need to come up with a clever way to fix this.