[CR] Add dexterity nerfs as explanations for melee misses

The list of melee miss explanations is stored with the player, and
added to when the effects on the player are applied each turn.
One issue with Evil artifacts is that they don't announce themselves as such: "Hi, I'm a nifty ring full of power from a mighty magic being who wants to conquer the world, but hit some bad luck with heroic types who cut me off of him.  You mind getting hold of those riders, you know, going around looking for Baggins, so they could give me a lift home?"

Something along the lines of "You've more pressing concerns than that insignificant speck!" (I'm sure there's a better way to phrase it) seems like a better fit.  The Evil Artifact convinces you that you don't *need* to be dextrous: you've got the artifact!