[xmonad] Floats always go to the current screen (Patch)

[Juraj Hercek]

Robert wrote:
> Yes, please test :) . To be honest I haven't yet tested it directly (I 
> only have multi-head at work). But shepheb on #xmonad helped test it 
> on his setup.
>
It works fine for me, tried on 3-head setup, everything works as 
expected, no float windows placed outside of currently focused screen.

-- Juraj