Bug 16794: Revise layout for Admistration > Patron categories

Bug 16794: Revise layout for Admistration > Patron categories

Add Bootstrap buttons and Font Awesome Icons to "Delete" and "Edit" links

To test
- Go to Administration -> Patron categories
 - Confirm that two button appear instead of links for "Edit" and "Delete"
 - Edit an existing category and confirm that works as expected
 - Delete a category and confirm that works properly.

Patch fix it according with QA comment 3
Fix copy and paste according with QA comment 6
Fix column "Default privacy" to be sorted again according with comment 8
Patch set squashed

Buttons appear now as requested in comment #3 (2 buttons, no action menu)

Re-tested, works as expected.
Signed-off-by: Marc Véron <veron@veron.ch>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>
Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>