Bug 25340: Pass biblio object to OPAC comments template

Bug 25340: Pass biblio object to OPAC comments template

This patch modifies the OPAC comments system so that the biblio object
is passed to the template. This allows the biblio-title include to
properly access the title and subtitle information.

Unrelated change: Remove some custom CSS from the page which was
obsolete.

To test, apply the patch and make sure the "reviewson" preference is
enabled.

- Log in to the OPAC and open a bibliographic record's detail page.
- Under the "Comments" tab, click the "Post your comments" link to
  trigger the pop-up window.
- In the pop-up window, verify that the item's title is correct in the
  page title and the heading. Author should display correctly, if
  present.
- Test submitting a comment and editing a comment. Everything should
  work correctly.

Signed-off-by: Sally <sally.healey@cheshiresharedservices.gov.uk>
Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>