First post-jam update

First post-jam update!

Fixed up one minor glitch and substantially nerfed the difficulty.

Added the ability for units to turn in place, and for fast units (chariots and beasts) to have different orders for their first and second moves. Also, all orders can be given by clicking on the arrows rather than just by keyboard.

Instructions are now in-game. Selecting or mouse-overing a unit will show that unit's stats and abilities.

Added WebGL, Mac, and Linux builds.