Search filter groups admin UI / API

Search filter groups admin UI / API

UI for managing search filter groups and group entries.

This inclues a new API call for performing CRUD actions on filter
group entries:

open-ils.actor.filter_group_entry.crud

This new API call was necessary because entries link to
actor.search_query's, whose write access cannot be controled by pcrud.

Signed-off-by: Bill Erickson <berick@esilibrary.com>
Signed-off-by: Kathy Lussier <klussier@masslnc.org>
Signed-off-by: Dan Scott <dscott@laurentian.ca>