gfse: better integration of the minibar

The minibar is now displayed inside the editor, intead of on a separate page.
This makes the context clearer and makes it more obiovous how to return to the
editor.

src/www/minibar/minibar.css

@@ -1,4 +1,4 @@
-body {
+body.minibar {
     background: #ccc url("brushed-metal.png");
 }