Bug 9646 - Replace YUI button on the printers administration page with Bootstrap

Bug 9646 - Replace YUI button on the printers administration page with Bootstrap

This patch converts the toolbar on the printers administration page to
Bootstrap, replacing YUI button code with Bootstrap markup.

To test, view the printers administration page and confirm that the "New
printer" button looks correct and works correctly.

Signed-off-by: Bernardo Gonzalez Kriegel <bgkriegel@gmail.com>
Comment: Works well. No errors.
Off-topic: How do you access this page? I can't find a link
(tested using .../cgi-bin/koha/admin/printers.pl)

Signed-off-by: Katrin Fischer <Katrin.Fischer.83@web.de>
Works well, no problems found.
Accessed printers page manually: /cgi-bin/koha/admin/printers.pl
Signed-off-by: Jared Camins-Esakov <jcamins@cpbibliography.com>