Fixup on description and some option descrips

Also there's a TODO in there about needing to do some checks about the presence and readability of a dictionary file, @jvazquez-r7 . I'm not a fan of having a required file option that doesn't point at a file that we already know is there -- perhaps you can pick out the unix user list that lives in data/wordlists and prepopulate that? It just makes it harder to run this module automatically.

Not a blocker for release, unless you care to commit in the next 15 mins.