Update hooks admin area to reflect new area

The hooks area was moved from addon to maintain but the form urls were not changed.
Also added a redirect when removing a hook, this because the hook list was loaded prior to the deletion so the 
list (on deletion) was stale.
Couple of minor tweaks to the editor css, also renamed the file to maybe avoid some confusion.
Fixed some small formatting things, mostly noted when working on the solved topic mod, to lazy to create a PR just for them!