Refactor vector system to be cleaner

- Move Vector, etc. into `.math` package
- Drop many methods that will be auto-promoted anyways, eg. with
`divide(int)` and `divide(double)` the first is now gone.
- Take Block vectors into their own class hierarchy
- Make it clear throughout the API what takes blockvectors
- many more improvements

worldedit-core/src/main/java/com/sk89q/worldedit/WorldEdit.java

@@ -40,6 +40,7 @@ import com.sk89q.worldedit.extension.platform.PlatformManager;
 import com.sk89q.worldedit.extent.inventory.BlockBag;
 import com.sk89q.worldedit.function.mask.Mask;
 import com.sk89q.worldedit.function.pattern.Pattern;
+import com.sk89q.worldedit.math.BlockVector3;
 import com.sk89q.worldedit.scripting.CraftScriptContext;
 import com.sk89q.worldedit.scripting.CraftScriptEngine;
 import com.sk89q.worldedit.scripting.RhinoCraftScriptEngine;
@@ -370,7 +371,7 @@ public class WorldEdit {
      * @return a direction vector
      * @throws UnknownDirectionException thrown if the direction is not known
      */
-    public Vector getDirection(Player player, String dirStr) throws UnknownDirectionException {
+    public BlockVector3 getDirection(Player player, String dirStr) throws UnknownDirectionException {
         dirStr = dirStr.toLowerCase();
 
         final PlayerDirection dir = getPlayerDirection(player, dirStr);
@@ -382,7 +383,7 @@ public class WorldEdit {
         case NORTH:
         case UP:
         case DOWN:
-            return dir.vector();
+            return dir.vector().toBlockPoint();
 
         default:
             throw new UnknownDirectionException(dir.name());