- EWMH support can certainly be improved.

- Persistent clients (ok, aepanel-*) should reload their config files
  on SIGHUP.

- Obscure parts of the ICCCM that need to be implemented: WM_COLORMAPS,
  WM_TAKE_FOCUS. Shouldn't be very difficult, I just have no pressing
  need for them currently. I will bring back wm_cmap_wins[1] when I do
  this.

[1] wm_cmap_wins = XInternAtom(dpy, "WM_COLORMAP_WINDOWS", False);
