Fix 'This field is required' errors. No idea why we didn't see this before.

First stab at some location coverage.

See merge request !84

CSS styling and template reorganisation

See merge request !80

This template is still broken (data-view URL). Not sure if we need it

Add the upload form to the base template

See merge request !83

Move the form rendering to a template tag. If we don't want the form to appear in a tab,
we just need to remove 'source' from the tab settings.

Re-enable buttons that were accidentally disabled in 942971a4

See merge request !82