[xmonad] StackTile, a new tiling algoritm.

[Don Stewart]

acura:
> I recentley started to use xmonad again after a while with DWM.
> With DWM i used a patch that gave me a tilingalgoritm that stacked the
> windows like in the dishes tiling, but with the ability to resize the
> master pane. I did'nt find such a path for xmonad so I wrote my own. I
> find this kind of tiling superior on small screens.
> 

Great to see a new contributor. Welcome.

Your patch has been applied.

-- Don