[dev] wmii fix changing resolution

[Ming Wang]

Sometimes when the screen changes resolution, WMII fails an assert in 
x11.c reshapewin() and quits (instead of dynamically rearranging the windows to 
fit the new screen size). This typically happens when using WMII in a
 VMWare or VirtualBox guest, and changing the size of the window in the 
host. It is very annoying that WMII quits and X terminates and all my 
windows in the guest are lost. So here's a patch that works fine for me.
http://pastebin.com/WkPJfxaK

Cheers
W-