Makes wizard hat defenses match the robe.

So many moons ago, wizard robes had full body coverage. But that got changed because not even magic can explain that bullshit.

However, this had the side effect of leaving a wizard's poor noggin vulnerable and exposed to the lasers, floor tiles, harmbatons, and whatever else the station could throw at them, as the wizard's head was no longer covered by the full body robes, yet the hat never got defense stats to compensate.

Fake robes and hats from costume crates and the autodrobe don't have any defense, though wizards can still cast robed spells just fine with them. I'm unsure if that's intentional or not.

My first PR, whee.