Fix small/big hood, connect instant win depth.
xorshift initializes itself properly already.
Various havannah board improvements.
Stop using the move specializations.
Pull out two ring policies that don't seem to work, and move the other two partially into the board itself.
Move the movelist out into its own file.
Switch from local to patterns, which is more general and allows future things. Might be worth making optional in the future.
Move the policies into policy files, to match Y.
Bring havannah and Y closer together again.