Query Parser nested dynamic filters

Query Parser nested dynamic filters

Dynamic filters (from metabib.record_attr) are now parsed along with
search strings and facets as Query Parser descends the parse tree.  The
WHERE clause for the query as a whole is now a combination of the main
WHERE and the ON clause for JOINing to metabib.record_attr.  This gives
us the ability to create complex boolean nested queries using
SVF/record_attr filters, unlike before where nested filters were either
ignored or always treated as global filters.

For example:

concerto && ( ( item_type(a) subject|topic[Music] ) || item_form(a) )

This query now successfully limits the "concerto" search to results that
have either (item_type(a) AND subject|topic[Music]) OR item_form(a).

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