Bug 1633 - [SIGNED-OFF] Add ability to take book cover images from local img db

Bug 1633 - [SIGNED-OFF] Add ability to take book cover images from local img db

OPAC Template revisions:

- Revised OPAC imageviewer template to match structure of
  other OPAC pages (with masthead search, footer, etc)
- Added link back to detail page (controlled by
  BiblioDefaultView preference)
- Added link style to thumbnails on opac-detail to add a sense of
  "clickability" to them
- Revised OPAC imageviewer template to allow it to function
  with JavaScript turned off. Now even without JS main image
  will load, thumbnails will be properly styled, and thumbnail
  links will work.
- Changes to the script are only to pass missing variables
  to the template

TODO: Corresponding changes for the staff client
Signed-off-by: Jared Camins-Esakov <jcamins@cpbibliography.com>
Signed-off-by: Magnus Enger <magnus@enger.priv.no>
Signed-off-by: Koustubha Kale <kmkale@anantcorp.com>