Significantly improved dialog display and input delegation

Something fairly substantial on the client side this time, though it might not look that way. :)

Two important things are now happening. First, dialog has pagination! I started off with text that was too long to show in one box, since the worst case scenario is usually the best place to begin. That's handled now.

More importantly, though, there's now a stack of input targets. So if you're the top menu (or whatever, provided you implement the right interface), you'll get input only when you should. So in this gif, even though you can't see it, I'm button-mashing while the dialog is up but my poor sorceress just isn't going anywhere, since she's not at the top of the input stack.

I'm also really fond of the little bouncy triangle.