plasmidpredictor_database_downloader shouldn't download surprisingly

[tseemann]

% plasmidpredictor_database_downloader
Downloading data with:
curl -X POST --data "folder=plasmidfinder&filename=plasmidfinder.zip"

Noooo! whats going on. whats all this scrolling. whats happened??

I think --outdir should be required ... "principle of LEAST SURPRISE".

Most people expect to see --help to stderr when no parameter supplied.

[andrewjpage]

Fixed