Bug 16045 - Use Font Awesome icons in OAI sets administration

Bug 16045 - Use Font Awesome icons in OAI sets administration

There are links on the OAI sets administration page which can use Font
Awesome icons instead of being styled with background images. This patch
makes that change.

Another minor change: Added the "fa-fw" class to items in the "Actions"
menu which didn't have it. This helps the items line up correctly:
http://fortawesome.github.io/Font-Awesome/examples/#fixed-width

To test, apply the patches for Bugs 16014 and 15991 if necessary. Apply
this patch and:

- Go to Administration ->  OAI sets configuration.
- Click the "New set" button and verify that the "Add description" link
  uses a Font Awesome icon.
- Confirm that the "Add description" link works correctly.
- After adding a description, verify that the "Remove" link looks
  correct and works correctly.
- From the list of OAI sets choose "Define mappings" from the "Actions"
  menu.
- Confirm that the "Delete" button is styled correctly and works
  correctly.

Signed-off-by: Aleisha <aleishaamohia@hotmail.com>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>
Signed-off-by: Brendan Gallagher brendan@bywatersolutions.com