Implemented drone sprite, basic AI

core/src/io/anuke/mindustry/content/UnitTypes.java

@@ -1,13 +1,14 @@
 package io.anuke.mindustry.content;
 
 import io.anuke.mindustry.entities.units.UnitType;
-import io.anuke.mindustry.entities.units.types.Vtol;
+import io.anuke.mindustry.entities.units.types.Drone;
 import io.anuke.mindustry.entities.units.types.Scout;
+import io.anuke.mindustry.entities.units.types.Vtol;
 
 public class UnitTypes {
     public static final UnitType
 
-    drone = new Vtol(),
+    drone = new Drone(),
     scout = new Scout(),
     vtol = new Vtol();
 }

core/src/io/anuke/mindustry/content/blocks/ProductionBlocks.java

@@ -59,9 +59,6 @@ public class ProductionBlocks {
 
     plasmadrill = new Drill("plasmadrill") {{
         heatColor = Color.valueOf("ff461b");
-        //TODO
-        //inputLiquid = Liquids.plasma;
-        //liquidRequired = true;
         drillTime = 110;
         size = 4;
         powerUse = 0.7f;