Move diligency table to bottom of page.

Not that useful in most cases, only if you wanted some admin
competition on category entering/checking. Fixes #739.
Tweak summary output on bodies page.

Show more detail of unconfirmed/deleted categories; highlight and warn
if no categories, or if all categories are deleted. Fixes #516.
Validate category name/email/note in admin.

This prevents the creation of a category with a blank name. Fixes #556.
Prevent overhang of admin body categories table.

Group things together more simply. Fixes #738.
Merge remote-tracking branch 'origin/issues/516-body-warning'
Merge remote-tracking branch 'origin/issues/739-move-diligency-table'