supported ID attribute.

git-svn-id: https://hudson.dev.java.net/svn/hudson/trunk/hudson/main@1402 71c3de6d-444a-0410-be80-ed276b4c234a

core/src/main/resources/lib/layout/pane.jelly

@@ -5,7 +5,7 @@
   <%@attribute name="width" required="true" %>
 -->
 <j:jelly xmlns:j="jelly:core" xmlns:d="jelly:define">
-  <table class="pane">
+  <table class="pane" id="${attrs.id}">
     <tr><td class="pane-header" colspan="${width}">
       ${title}
     </td></tr>