Bug 3056 - replace span hacking for terms in C4::Search

Bug 3056 - replace span hacking for terms in C4::Search

Reimplemented using jquery, added OSS plugin to both interfaces.  This is
another case where having a /common directory used by both OPAC and STAFF
would increase runtime efficiency and cut development time.

Removed unused variables.

I changed the OPAC .term color to match the staff interface, rather than being a
second shade of blue.  The highlight/unhighlight link is currently a bit bolder
than its neighbors, but my styling choices are provisional.  I expect the final
tweaking of CSS to come from another more capable designer, like Owen.

Note this patch may rely on previously submitted "Search.pm minor cleanup" patch.

Signed-off-by: Galen Charlton <galen.charlton@liblime.com>