Cleaned up a lot of code and introduced Kotlin to the project

worldedit-core/src/main/java/com/sk89q/worldedit/regions/EllipsoidRegion.java

@@ -34,6 +34,7 @@ import com.sk89q.worldedit.world.storage.ChunkStore;
 
 import java.util.HashSet;
 import java.util.Set;
+import org.jetbrains.annotations.Range;
 
 /**
  * Represents an ellipsoid region.

worldedit-core/src/main/java/com/sk89q/worldedit/regions/Region.java

@@ -319,6 +319,7 @@ public interface Region extends Iterable<BlockVector3>, Cloneable, IBatchProcess
         }
     }
 
+    @Override
     default Extent construct(Extent child) {
         if (isGlobal()) {
             return child;