Discrimination shows promise. :) Also, dataGen and sampleFunctions were changed to allow for s+b functions.

Changes to be committed:
modified: debinningCore/vsHistogram.py
modified: debinningMath/dataGen.py
modified: debinningMath/sampleFunctions.py
modified: examples/debinningDemo.py
modified: examples/discriminationMC.py
modified: examples/nfrDemo.py
modified: examples/zeroVarianceLimit.py