Restrict the download option to Firefox for now, and disable the external XML link for saved machines

modules/shared/lib/embed.js

@@ -156,6 +156,7 @@ function parseXML(sXML, sXMLFile, idMachine, sParms, fResolve, display, done)
              *
              * Until/unless that changes, components.xsl cannot be simplified as much as I might have hoped.
              */
+            if (typeof resources == 'object') sURL = null;      // turn off URL inclusion if we have embedded resources
             sXML = sXML.replace(/(<machine[^>]*\sid=)(['"]).*?\2/, "$1$2" + idMachine + "$2" + (sParms? " parms='" + sParms + "'" : "") + (sURL? ' url="' + sURL + '"' : ''));
         }
         /*