Fixes for longbow (1)

Fixed what is probably the main cause of longbow (1) - namely, trying to fire a bow with insufficient strength (since the strength check erroneously came AFTER the reload check).

Also made it so that loaded bows can be fired - if we're in a buggy state, let's let the user get out of that buggy state in an obvious way, rather than a non-obvious way.

Thanks to FunnyMan for the reproduction steps in #658.