Add jdk1.4 friendly getCause() method

git-svn-id: https://svn.apache.org/repos/asf/ant/core/trunk@273086 13f79535-47bb-0310-9956-ffa450edef68

src/main/org/apache/tools/ant/BuildException.java

@@ -165,6 +165,16 @@ public class BuildException extends RuntimeException {
         return cause;
     }
 
+    /**
+     * Returns the nested exception, if any.
+     *
+     * @return the nested exception, or <code>null</code> if no
+     *         exception is associated with this one
+     */
+    public Throwable getCause() {
+        return getException();
+    }
+
     /**
      * Returns the location of the error and the error message.
      *