Rudder

I saw missing favicon several times on the new doc (especially on first visit). The browser tries to download the file http://www.rudder-project.org/doc/favicon.ico (which does not exist), because the webhelp code links explicitly to this file. There is a favicon.png in the sources, but it is not the favicon we currently use on rudder-project.org (it has a black background).

We should replace the old favicon with the new one, favicon.ico, wich would then match the link in webhelp (we could also link to /favicon.ico directly, but that would not work in the embedded doc as the Rudder webapp favicon is /rudder/images/rudder-favicon.ico).