Bug 18134: Updating Preview MARC button in Batch Authority Record Mod

Bug 18134: Updating Preview MARC button in Batch Authority Record Mod

This patch ensures the Preview MARC button when batch modifying
authority records looks like the Preview MARC button when batch
modifying biblio records.

To test:
1) Go to Tools -> Batch record modification
2) Leave record type as Biblio, Put in a biblionumber, select a template
and click Continue
3) Notice the 'Show MARC' button
4) Click Cancel and change record type to Authority. Put in auth id,
select template, click Continue
5) Notice ugly 'Preview MARC' link
6) Apply patch and refresh page
7) There should now be a nice 'Show MARC' button like there is for
biblio mod. Confirm it still works as expected.

Sponsored-by: Catalyst IT
Signed-off-by: JMBroust <jean-manuel.broust@univ-lyon2.fr>
Signed-off-by: Nick Clemens <nick@bywatersolutions.com>
Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>