Don't show disabled snippets in public view and fix admin bulk save.

Bulk save in the admin was broken because it uses save_model, which
assumed there was a `locales` field in the form. However, the form
used for saving multiple snippets at once doesn't have this field and
caused errors. So, we update save_model to be able to accept forms
without a `locales` field.

Also removes disabled snippets from the public view and updates the public view to show the full title of snippets and wrap them to multiple lines. Also fixes some of the markup for the public view table.