r17598: Patch from Martin Kühl <mkhl@samba.org> to update the samba3sam test

r17598: Patch from Martin Kühl <mkhl@samba.org> to update the samba3sam test
suite, which contains tests for the samba3sam and ldb_map modules,
with a lot of tests for search requests.

The tests add a small set of known records to the database, half of
them with only remote data, half of them split across the local and
remote backends, and test searching these records by DN, by attribute
and with a range of parse trees.

This suite should be extensive enough to ensure that behaviour of
search requests doesn't break.
(This used to be commit 120f7891faf241057457db7234ce381bfe3fd847)