The DrupalCon bug -- node administrator privileges kills DISTINCT

At the conf, moshe pointed out a bug, and JonBob and I fixed it on site.

The $return['distinct'] in the past should have been module_implements('node_grants') but after JonBob's node_access_view_all_nodes, that part happens only if node_grants is in effect, so it is simplified to 1.

This orphans module_implements, but my module.inc patch uses it, so it won't be an orphan after all.