Merged in ENGINE-250 - foreign keys are now on, as they should have been forever.

ENGINE-250: foreign keys are now on and tests pass. Be aware that with the amount of time we may have been running with them off, there may be other execution paths that cause trouble. File bugs against any DB errors.

Probably own identity issues.

ENGINE-250: address fixes and more; lower() still does something really goofy on the FIRST run with make test, but only then, and even if all databases and keyrings are removed, case_and_dot_address_test still passes for every time after until the next time you make clean *with the whole engine* and rebuild. BIZARRE.

ENGINE-250: Pretty sure the current bugs are now actual bugs and not sql-related. But will check. insert-or-replace for identity-based set functions is now replaced with a slightly convoluted callback mechanism which does a check for existence and then updates or inserts appropriately, with optional transaction guards (to be set to false if they're called in what's already a transaction, e.g. set_identity)

ENGINE-250: Marginally working, but changes() doesn't seem to be a sufficient way of differentiating between update and insert. COuld be my bug though. Some tests still fail, but we need a commit here.

ENGINE-250: fixed some things, am screaming at others. Have overcome the 'insert or update' issue at least, probably.

Intermittent commit

Merged in fixes for ENGINE-352, ENGINE-345, a bunch of trust/mistrust issues, and general mayhem.

closing branch