Betrayer: Add water vertex shaderr dumped from game
Betrayer: Messing around with water shader

Trying this out without really knowing what I'm doing, but I have had some
success - this change actually fixes the water... from exactly one angle.

I know there's a couple of things wrong with the stereo formula - I was messing
around to see what happened, but this partial success is still worth
committing until I work out how to fix it properly.