code: public WebApplicationContext[] addWebApplications(String host,
                                                        String webapps,
                                                        String defaults,
                                                        boolean extract)
          throws IOException
      {
          return addWebApplications(host,webapps,defaults,extract,true);
      }
docs: Add Web Applications.
  Add auto webapplications to the server.  The name of the
  webapp directory or war is used as the context name. If the
  webapp matches the rootWebApp it is added as the "/" context.
  @param host Virtual host name or null
  @param webapps Directory file name or URL to look for auto
  webapplication.
  @param defaults The defaults xml filename or URL which is
  loaded before any in the web app. Must respect the web.dtd.
  If null the default defaults file is used. If the empty string, then
  no defaults file is used.
  @param extract If true, extract war files
  @exception IOException