Bug 16439: Allow styling to button for upload local cover images (Font Awesome Icons)

Bug 16439: Allow styling to button for upload local cover images (Font Awesome Icons)

Improve button for upload local cover image with Font Awesome Icon

To test:
-Set syspref LocalCoverImages and OPACLocalCoverImages to Allow
-A new tab 'Images' appear in bib record detail on Intranet.
-Notice about the button upload.
-Apply the patch and reload the page.
-The button is changed for class=btn btn-mini like the button "edit"
 used in items in the tab Holdings
-Also added the Font Awesome icon upload "fa fa-upload" class.

Button is styled as expected.
Signed-off-by: Marc Véron <veron@veron.ch>
Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Brendan Gallagher <bredan@bywatersolutions.com>
(cherry picked from commit 6003c6b320a4fec0be37b4940a676dfdfa1875f4)
Signed-off-by: Julian Maurice <julian.maurice@biblibre.com>