Smoke Grenades Done

Just finished implementing the smoke grenades. These will block every unit's line of sight, so, use them wisely. Since smoke grenades are a defensive weapon, they will mostly be used for escaping or retreating units into safer areas.

The CPU units seem to handle smoke grenades well, side-stepping the smoke in order to find a suitable place with a line of sight. My next step will be coding the CPU units to use both explosive and smoke grenades. I'll have to think about the best approach to use them effectively.

Stay safe!