[PATCH] bug_7420: Added overduefinescap to issuingrules

[PATCH] bug_7420: Added overduefinescap to issuingrules

Replaced existing MaxFine syspref logic with overduefinescap.
Repurposed MaxFine to be the overall overdue limit for all items
overdue. Implemented new MaxFine logic in UpdateFine().

Signed-off-by: Elliott Davis <elliott@bywatersolutions.com>
Tested according to Srdjan's test plan and everything worked like he said it would.  I set fined equal to $2 and max fine equal to $1.      When I ran the fines script for overdue items fines assessed were only $1.

Signed-off-by: Paul Poulain <paul.poulain@biblibre.com>