Wrapped attrs.pubdate in search results with a span.class

- Used class="record_year" to indicate the "year" (date) field in
  search results.

Signed-off-by: William Rockwood <wrockwood@tadl.org>
Merge branch 'rel_2_2' of hades.lib.tadl.org:/opt/git/Evergreen_templates_tadlskin into rel_2_2