1. Got rid of the "create or replace function" decls used for triggers, due
to the brand-new PG 7.3 "opaque" vs. "trigger" issue.
2. Added a new "fs::get_folder_object_ids" for use when you just need the
object ids rather than a bunch of (slow) permissions information,
(slow) counts of items in folders and subfolders, last modified info,
etc. dotLRN was calling "fs::get_folder_contents" when cloning folders
despite making use of only the object_id and that proc used to be unimaginably
slow. It's faster now due to the new permissions code but it's still slow
enough to warrant avoiding it when possible.
3. Fixed typo in my last commit.
