Hold requests in the middle layer now bubble up more specific information to

Hold requests in the middle layer now bubble up more specific information to
the caller in the event of failure.

The caller can find an ilsevent in the response received from calling
open-ils.circ.title_hold.is_possible, and this event will have a fail_part
attribute in its payload that can be mapped either to a) the new entities
in opac.dtd or b) values of the name column of the database table
config.standing_penalty, depending on why a hold request failed.

git-svn-id: svn://svn.open-ils.org/ILS/trunk@16651 dcc99617-32d9-48b4-a31d-7c20da2025e4