Bug 16861: Translatability: Fix separated "below" in circulation.tt

Bug 16861: Translatability: Fix separated "below" in circulation.tt

This patch propose to fix this two entries in PO files:

"See highlighted items" and "below"

Also add some Font Awesome Icons

To test:
-Apply patch 16810 on top and this patch
-Go to a patron who has overdues
-See the link "See highlighted items below" with a hand down icon
-Look the new plus icon to "Add a new message" to the patron.
-Add a few messages and notice about the trash icon in "Delete" links

Signed-off-by: Marc Véron <veron@veron.ch>
Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Brendan Gallagher <brendan@bywatersolutions.com>