[OPEN-ILS-DEV] After upgrade to 3.0.2, OSRF query fails to limit items by org_unit

[Ken Cox]

After a lot of debugging, I figured out how to get search working
again in the Android app.

This query works in 2.12 but not in 3.0.2:

    method = open-ils.search.biblio.multiclass.query
    param = {org_unit=7, default_class=title, offset=0, limit=200, depth=2}
    param = "harry Potter chamber of secrets"
    param = 1

This query works in both:

    method = open-ils.search.biblio.multiclass.query
    param = {offset=0, limit=200}
    param = "title:harry Potter chamber of secrets site(ARL-ATH)"
    param = 1

I got a clue after seeing this comment in Biblio.pm:

> sub multiclass_query {
>    # arghash only really supports limit/offset anymore
>    my($self, $conn, $arghash, $query, $docache) = @_;

The funny thing is, that comment existed in 2.12 as well, and the
query worked there.

I kind of used https://wiki.evergreen-ils.org/doku.php?id=documentation:technical:search_grammar
as a guide though it's clearly not authoritative.  For instance,
site(7) should work according to the wiki but it doesn't, and
site(ARL-ATH) does.

Ken