Bug 14915: Use Font Awesome instead of Glyphicons for the staff intranet

Bug 14915: Use Font Awesome instead of Glyphicons for the staff intranet

We should be using Font Awesome for our icons instead of Glyphicons, for
the reasons discussed on bug 13696.

Test Plan:
1) Apply this patch
2) Note all Glyphicons have been replaced with FA icons in the staff intranet
3) git grep "icon-" ./koha-tmpl/intranet-tmpl/prog/en/modules/
   should give no results
4) git grep "icon-" ./koha-tmpl/intranet-tmpl/prog/en/includes/
   should give no results

Signed-off-by: Marc Véron <veron@veron.ch>
Signed-off-by: Katrin Fischer <Katrin.Fischer.83@web.de>
We need a follow-up to cover the files changes since this
patch was written. Especially to cover the changes in the
label creator modules.
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>