Mac support added (beta), change game speed, larger unit cap

-Mac support added. Let me know if there are any issues. (Steam overlay might be broken on Mac, I'm working on a fix) -Can speedup or slow down or pause singleplayer games with +/- buttons. Btw you can queue up commands while game is paused. -Doubled unit cap in singleplayer (and added hidden setting to customise it) -Fixed bug in adv mode skirmish unit cap causing it to be lower than it should (so it's unit cap is now quadrupled with above change) -Fixed click and drag mouse actions being ignored when placing buildings -Fixed click and drag action being ignored when using in-game buttons -Fixed mouse wheel zoom not working just after using the mini-map

This again should be compatible in multiplayer with the last version. Let me know if there are any issues.