PLEASE SCRUTINIZE: Eliminated bivalve() function.
Reasons:
- you can't be TOTING a clam
- carriable oyster is only at the endgame
- you can't have the trident at a carryable oyster, because inventory is emptied
- only called in lock()
- the code IMHO is more readable this way
These are my theories, and they do pan out in the tests, but that doesn't mean there aren't states I'm not accounting for.