13/9/11
  Added back horizontal tiling, follow mouse and follow window

12/9/11
  Returned to catwm tiling methods - with the ability to resize the window at the top of the stack

9/9/11
   Fine tuned the next/prev desktop and the destroy notify functions

 8/9/11
    Have a proper destroy notify function now that removes destroyed windows from
     the window manager stack for the desktop they were on.