Barkai Annotated features

[cmatKhan]

Create 2 barkai annotated features:

1. calculate normalized enrichment. Use that to create a distribution for each promoter, and then use that to provide both a 1-sided (x>=X) and 2 sided score (b/c with this promoter distribution method, it isn't unreasonable to look at promoters that are depleted I think. not quite sure yet)

2. Also call enrichment against the Mahendrawada 25 and Hahn controls (like Mahendrawada)