Add the new utils plugin, change entity spawning and the lookup command plugins to use it.

data/plugins/util/command.rb

@@ -0,0 +1,11 @@
+
+# Checks whether the amount of arguments provided is correct, sending the player the specified message if not.
+def valid_arg_length(args, length, player, message)
+  valid = length.kind_of?(Range) ? length.include?(args.length) : length == args.length
+
+  if (!valid)
+    player.send_message(message)
+    return false
+  end
+  return true
+end