setting WM_CLASS of matplotlib figure windows

Hi all,

I'm using matplotlib-0.99.1 (with backend Qt4, I don't have Tk backends
installed to compare there) on a netbook with Ubuntu netbook remix,
which includes maximus, a window manager which maximizes screen usage on
little screens. It chooses to maximize/not maximize new windows based
upon their WM_CLASS. Since I don't want to maximize matplotlib figures,
I add the matplotlib window WM_CLASS to an exclude list.

A quick check shows that matplotlib (or at least the Qt4 backend)
doesn't set the WM_CLASS of its windows:

xprop | grep WM_CLASS # click on matplotlib figure

WM_CLASS(STRING) = " ", " "

I'm not that familiar with the innards of matplotlib, so I'm not sure if
this is something that is possible to set in user-space, or if this is
something missing from the backend. Ideally this would be set to
something useful by matplotlib/the backend, but I'd settle for a quick
way of setting it manually.

Thanks for the advice!