Set minimum password length of 6

fixes #161 on github.
Merge pull request #162 from steventlamb/bug/minimum_password_length

Set minimum password length of 6
Merge pull request #160 from steventlamb/bug/species_csv_field_order

Bug/species csv field order
Migrate urls to use namespace

Fix url resolve crash pages in importer
Add optional extra fields to species export

Fix unicode crashes in CSV export by encoding to utf-8.

wip. works with extra fields included.

fixup extra fields included
Add test for species csv export