multiple changes, read comments please

- fixed all the cleanup/cleanhouse stuff to only close the search
  options if the search options slider is already open, and they
  now use the proper function to do so instead of doing it with
  jquery from scratch each time (because the function also flips
  the icon).
- added a placeholder logo for "branding" *hand waving air quotes*
  more branding shall ensue (Monday).
- cleaned up search options panel a bit (darkened the background,
  aligned the "limit to available" thing.)
- removed the dead "home_url" var from main-vars (we should audit vars)
- we should figure out how to deal with this list:
  https://catalog.tadl.org/eg/opac/results?bookbag=19142;page=0;locg=22;depth=0
  (when I view that list of mine, the <> are not correctly converted
  to htmlentities and the + are not correctly urlencoded.

Signed-off-by: William Rockwood <wrockwood@tadl.org>