Bug 15775: Show message on OPAC summary if holds are blocked due to fines

Bug 15775: Show message on OPAC summary if holds are blocked due to fines

To test:
1) Set maxoutstanding syspref to 5
2) Create a manual invoice for a borrower for $6
3) Log in to the OPAC as this borrower
4) Go to opac-user.pl, your summary page
5) Confirm there is a warning box explaining that the borrower is
blocked from holds due to fines
6) Back on the staff side, pay some or all of the borrower's fines so
they are no longer over the max outstanding amount
7) Refresh the summary page in the OPAC and confirm the warning is gone

Sponsored-by: Catalyst IT
Signed-off-by: David Nind <david@davidnind.com>
Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>