Added method for distances

I haven't even tried running it but it's here. I'll next try to run it
and start designing some tests.
New test for private fnc in star module
Working on novel donor/acceptors dists, tests

I need to merge in some changes from master.
Merge branch 'master' into dists

Conflicts:
	cdpybio/star.py
Fixed fnc for novel donor/acceptor dists

Also added tests.
Novel don/acc dist updates, tests