Fixed absolutely pinned tigers being unable to attack.
This is accompanied by a change to have possibleMoves use Game::move instead of Board::move, and a change to check for a move putting oneself in check.
Fixed a bug where white's midline victory line was one line too close.
Fixed a bug where loking at the possible moves for a pawn immediately after a friendly adjacent pawn took two forward steps would show a diagonal move as possible.
Merge branch 'master' of https://github.com/austonst/chess2