stored procedure for autosuggest

stored procedure for autosuggest

take:
 query string, like 'foo' or 'foo & ba:*', ready for to_tsquery()
 search_class (class|field|field...)
 markup options for ts_headline()
 optional org unit for opac visibility test
return:
 record id
 marked up matched value
 metabib field where found
 rank
 search_class bouyancy

I think this is mainly Right, except for the ranking/sorting, which I will
revisit.  But aside from sorting, the results of this function make
sense to me.

Signed-off-by: Lebbeous Fogle-Weekley <lebbeous@esilibrary.com>