Add schemas and amend the advanced search to allow for date and boolean queries

Allow negation of first field of staff advanced search

Clean up staff advanced search fields, reorder so they read better, and also prettify with some CSS

And fix I18n for suppressed in the boolean field list.

Fix date operation not sticking

Create enumerations for the date and boolean field values (provide some default entries)

Initialize a combobox for field lists with items greater than the min combobox limit

Modify backend search to allow for date ranges from the advanced search form (boolean searches follow same syntax as text searches)