v1.6

• fix bug where AI attackers could stall in the middle of the map
• fix bug where AI sometimes didn't repair buildings
• fix bug where a worker ant could drop resources off at an opponent mound (now it goes back to queen)
• fix possible out of memory crash when there are too many active units
• fix bug where mounds could take an extra long time to register as drop-offs
• added sfx to difficulty selection in title screen

also, here's a video of me beating 2 hard AIs if you're interested: