create-hold call now only accepts a single hold arg. that's how it was being used...

create-hold call now only accepts a single hold arg.  that's how it was being used and it makes the most since considering the return events are not hold-specific.  now, return the new hold ID on successful creation.  also tweaked potential copies count to use json_query count transform

git-svn-id: svn://svn.open-ils.org/ILS/trunk@13822 dcc99617-32d9-48b4-a31d-7c20da2025e4