Search Filter Groups and Generic Queries : DB / IDL

Search Filter Groups and Generic Queries : DB / IDL

Adds 3 new tables.  The first is a general purpose container for
query-parser queries.  These can be used by other entities for storing
saved searches, saved search filters, etc.  Each contains a query string
and a label.

The two other tables are for creating org unit saved search filter
groups.  A filter group is a named set of search queries, treated as
filters, collected to create a high-level search filter.  Filter group
entries use search_query's under the covers, so the content of the
filter can be any valid query string, including other filters or even
other filter groups.

For example, you could create an "Audience" filter group with entries
like, "Children" => "audience(a, b) locations(3,4,5)" to filter on copy
location in addition to the MARC audience data.

Signed-off-by: Bill Erickson <berick@esilibrary.com>
Signed-off-by: Mike Rylander <mrylander@gmail.com>