[dwm] append window patch for dwm-3.8

[pancake]

I've updated the append window patch for dwm-3.8. It's a little buggy when 
zooming, but
it's an initial implementation. These days I have been thinking about the 
*real* importance
of this patch, and I think that it can be confusing for the end user, but 
useful on certain
cases.

With this patch you can make new windows appear in head or tail of the window 
listing,
the zoom is done in the same way, when append window is set , the zoom is done 
to the
last client of the window list (call't inverse zoom or so.. :P )

The configuration is:

  toggleappend(0)   - normal tile
  toggleappend(1)   - append window on tile
  toggleappend(-1)  - swap between 0 and 1

My configuration is:

        { MODKEY,                       XK_a,           toggleappend,   "0" }, \
        { MODKEY,                       XK_s,           toggleappend,   "1" }, \


Have fun!

  --pancake