Fix alignments of FF 'warn' labels

Putting right-float span first fixes the alignment. Adding a margin to the
left of the element makes it not stick to the text.

Found some cruft while doing this, removed that as well
Fix unittests (database version bump)
Added dependency on uwsgi-plugin-python (fixes #344)
Improved suggestions for git problems (fixes #360)

When 'git init' has not been setup yet, some settings are incorrect.
Provide running 'git init' as one of the first suggestions. Also show the
'local SSH' check before the 'public SSH hostname' check.
Diagnostics: clarify email settings (fixes #359)

 * Only show 'sane' checks if *something* has been set
 * Repeat what the setting does in the sane checks