create script to standardize peak files

[ptrebert]

read macs2/histoneHMM peak files and standardize format; additionally, flag for blacklist/input enriched...

[ptrebert]

@HeleneLuessem
This script would be good candidate for some testing of intermediate results; it should be called at the end of both the narrow and the broad peak calling (and after the intersect step) and should produce format-wise coherent files for both Macs2 and histoneHMM