Please describe the problem:
The window list applet is not usable on a vertical (left/right) panel.

Steps to reproduce:
1. create a panel on the left or the right
2. add the window list applet to that panel
3. enjoy


Actual results:
There is only one window item which takes the whole width and height and isn't
even usable.

Expected results:


Does this happen every time?
yes

Other information:
Windows handle that by stacking boxes on top of each other, the result is a high
window capacity, but low readability.

The other way around could be to simply "rotate" the boxes, so it would look
exactly like a normal panel, but rotated 90 degrees. That result would be
similar to the rotated gnome menu applet.