Harvesters nearly done

I finally implemented harvesting! It's not fully done yet, as the harvester keeps on harvesting when it's full, and it doesn't accurately search for new spice when it's done with the current tile, but those are improvements I'm going to make over the course of the coming days.

Harvester enroute to the spice, MCV is moving in the background

Harvester feasting upon some spice

As you can see, harvesters have a 2nd indicator showing their fullness. Also, when I was writing the harvester code, I already implemented quite some code needed for attacking.

I initially thought about adding a Harvest() function, but soon figured out that a harvester would basicly attack the spice, so I override the Attack() function from the units now.

Coming week I'll finish the harvester completely by making it search better for spice, clean up some code and fix all the mess I wrote in the mouse handling code. Oh, and work out a better way for mass selected units, so that Harvesters don't attack units/buildings(Or attempt to) and that regular units don't attempt to attack the spice(Which would be catastrophic, as I intend to make the value of spice tiles decrease when they're hit with gun fire).