moved __main__ arguments into functions for import access

with hicluster and common_path needing to be run by external
scripts, the benefit of utilising the argument parser under
__main__ was made available in both by putting them into their
own functions.
created random_comp to allow comparison of multiple experiements

script utilises hicluster to generate two random data sets, then
compares the genes common to both (and common in the same or
different directions)