Evergreen driver enhancements: holdings & patrons

This branch includes a number of bug fixes:

* Generate a proper set of holdings for a given record, rather than returning the copy that shares the same ID as the record (which means that a random copy was being returned for each record).
* Return patron profiles for patrons who do not have a mailing address.
* Return the patron's primary profile name rather than the user group ID 
* Bind parameters to prepared SQL statements rather than interpolating variables directly to avoid SQL injection.