Bug 7741 [Follow-up] Clear search terms in Z3950 search page

Bug 7741 [Follow-up] Clear search terms in Z3950 search page

This patch makes a follow-up change and takes as its basis a dependency
on Bug 13218 - usability enhancement for z39.50 search. If we have a
one-column search form it's possible to put the "Clear search form" link
at the bottom of the form rather than in the header, logically
associating it with the grouping of form fields which will be affected.

Doing so also allows us to eliminate all the custom styling which was an
issue for QA.

Other changes made by this patch: Fixing the indentation
error, correcting the case of the link text ("Clear search form" instead
of "Clear Search Form"), and adding "preventDefault()" to the click
handler so that clicking the link doesn't scroll the user back to the
top of the page.

To test, apply the previous patch and this one on top of Bug 13218.
Repeat the test plan.

Signed-off-by: Jonathan Druart <jonathan.druart@biblibre.com>
Signed-off-by: Tomas Cohen Arazi <tomascohen@gmail.com>