Bug 18139: Display the rule critera used to determin the checkout limits to the template

Bug 18139: Display the rule critera used to determin the checkout limits to the template

The too many checked out message can be very confusing for librarians
when the limit specified is more or less than the number of checkouts
the patron already has. We should make it clear to the librarian that
his is only counting certain types of checkouts by giving them the
issuing rule criteria used.

Test Plan:
1) Apply this patch
2) Try to check out more items than the circ rules allow for
   regular and on-site checkouts

Signed-off-by: Eric Gosselin <eric.gosselin@inlibro.com>
Signed-off-by: Marc Véron <veron@veron.ch>
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>
Signed-off-by: Katrin Fischer <katrin.fischer@bsz-bw.de>