Add in warning banner

git-svn-id: https://svn.apache.org/repos/asf/ant/core/trunk@272502 13f79535-47bb-0310-9956-ffa450edef68

src/main/org/apache/tools/ant/taskdefs/optional/extension/Extension.java

@@ -70,6 +70,13 @@ import java.util.jar.Manifest;
  * Java2 Standard Edition package, in file
  * <code>guide/extensions/versioning.html</code>.</p>
  *
+ * WARNING WARNING WARNING WARNING WARNING WARNING WARNING WARNING
+ *  This file is from excalibur.extension package. Dont edit this file
+ * directly as there is no unit tests to make sure it is operational
+ * in ant. Edit file in excalibur and run tests there before changing
+ * ants file.
+ * WARNING WARNING WARNING WARNING WARNING WARNING WARNING WARNING
+ *
  * @author <a href="mailto:craigmcc@apache.org">Craig R. McClanahan</a>
  * @author <a href="mailto:peter@apache.org">Peter Donald</a>
  * @version $Revision$ $Date$