Comment 4 for bug 1241895

Workspace switcher doesn't recognize screen changes done by xrandr.

Steps to reproduce:

1) Start with a single-monitor configuration. For this example, I use the external screen VGA-0 attached to the laptop, while the laptop's LVDS is turned off.

2) `xrandr --output LVDS --auto --below VGA-0' makes the desktop extend to the laptop's LVDS, putting it below the external screen while the panels stay where they are.

Expected results:
Workspace switcher resembles the new screen size in its miniature view.

Actual results:
Workspace switcher still resembles the old screen size in its miniature view and seems not to know about the new screen configuration.

`xfce4-panel -r'