Support for 'Personal Menu' addon

[ukch]

On the default theme, the Personal Menu addon button renders as a (rather ugly) orange box containing an icon, the word 'Firefox', and a dropdown arrow. On the GNOME theme, it simply renders as the word 'Firefox'.
It would be great if the icon and/or the dropdown could render in this theme. I assume this is as simple as adding some sort of handler for the specific element types?