Changes mob stun()

Stun() will no longer make you drop what you're holding.

Most stuns weaken() as well. Weaken() knocks you over, thus dropping what you have in your hands. Most stun weaponry will still stun exactly like it used to. Coughing still makes you drop what's in your active hand I think.

Flashes have been reworked to disarm people like they used to (this is the assumption that the flash is so bright it makes people clutch at their eyes involuntarily, and also to make the flash not completely worthless as a tool for disarming people.)

Why? Because being stunned while standing up and dropping what you're holding is a really bad. Flashes are coupled with a bright white overlay, and electrodes/etc make you jitter now. Ideally, in the future, stun guns won't knock you down (weaken), just lock you in place and make you jitter like fuck so you aren't completely helpless, but you can still easily be knocked down with a stun baton follow-up.

Still, I'm keeping this PR separate from that, because regardless of whether or not I go with that or something, stun() should not be disarming people when it has no real reason to do so on its own.