Minor Description
When extjs isn't installed, the web UI page is currently unhelpfully blank (it has the oozie logo and docs link). In the past (when it used to be an html page instead of a jsp page) it had some text to let the user know that they have to install extjs to see the UI.
It would be good to put back the same or similar text; otherwise, users may be confused why they can't see the UI if they forget to install extjs.