Bug 32068: Consistent classes for primary buttons: Administration

Bug 32068: Consistent classes for primary buttons: Administration

This patch makes changes the button markup in Administration templates
so that all submit buttons and any buttons that should should be styled
as primary buttons have the Bootstrap class "btn btn-primary."

To test, apply the patch and view pages in Administration to confirm
that everything looks correct. In most cases there are no visible
changes.

Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>