Fixed 4096/256 block ID restriction in BukkitWorld.

src/main/java/com/sk89q/worldedit/bukkit/BukkitWorld.java

@@ -866,7 +866,7 @@ public class BukkitWorld extends LocalWorld {
      */
     @Override
     public boolean isValidBlockType(int type) {
-        return type <= 255 && Material.getMaterial(type) != null;
+        return type <= 4095 && Material.getMaterial(type) != null;
     }
 
     @Override