public static List<String> getServletNames( Document webXml )
    {
        return getNames( "servlet", webXml );
    }
Retrieves the names of all servlets from a web.xml document.

Returns a list that contains 'sessioncreate' and 'sessiondestroy' from this web.xml document:
&lt;servlet&gt;
  &lt;servlet-name&gt;sessioncreate&lt;/servlet-name&gt;
  &lt;servlet-class&gt;SessionCreateServlet&lt;/servlet-class&gt;
&lt;/servlet&gt;
&lt;servlet&gt;
  &lt;servlet-name&gt;sessiondestroy&lt;/servlet-name&gt;
  &lt;servlet-class&gt;SessionDestroyServlet&lt;/servlet-class&gt;
&lt;/servlet&gt;

@param webXml web.xml document, parsed as XML (cannot be null)
@return The name of the filter class, or null when no such class was defined.
xmppserver/src/main/java/org/jivesoftware/util/WebXmlUtils.java