Version 0.3.3

Differences from 0.3.0:

• Stun is a shared/core mechanic instead of being duplicated in a bunch of places. When a unit is stunned, it loses prepared orders, focus, and brace and can't act on the next tick. Weapon attacks and the flash spell stun. Unarmed attacks and magical damage do not.
• Dash move can't be used to run faster than bullets. The hallway overwatch problem needs to be fixed some other way anyway.
• Added some cover example diagrams.
• If you incapacitate someone with a melee attack, you can go for a nonlethal strike and choose to skip the death roll. This gives melee weapons a specific use for capturing enemies.
• Shields can act as cover for another unit standing behind the shield holder, consistent with modern spec-ops use of ballistic shields.