Bug fix and new features

[apcamargo]

I know that opening a PR with multiple unrelated fixes and new functions isn't ideal, but I've been working with this slightly modified version of enrichM and I decided to share my fixes and additions.

This PR does the following:

• Fixes write splits characters in module path header #105
• Fixes enrichm classify fails on blank lines in input file #104
• Fixes Database downloader is not working #103
• Splits Pfam and TIGRFAM HMM cutoffs into separate arguments. This way the user can use, for instance, --cut_ga for Pfam and --cut_nc for TIGRFAM.
• If two Pfam domains overlap the one with the highest E-value is discarded if both belong to the same clan. This behaviour is the same of pfam_scan.pl.

[geronimp]

Hey,

I really appreciate these additions, thanks for those bug fixes. I've just merged them in (some time later).

[apcamargo]

Thanks, @geronimp!

Another think that I did was to update all the databases (and their respetive pickles) to their latest versions. If you are interested, I can make those files available to you.