[dwm] dwm-1.6 large numbers of clients diff (includes xinerama)

Hi, in case it's useful to anyone a dwm-1.6 version of my
large numbers of clients diff (including a dotile() which
allows more columns for xinerama).

Hi, Anselm: not totally clear what the weight assignments are:
for any tiled client, its weight is precisely the numerically lowest
set tag?

The only noteworthy thing is that I've discovered that once
I've got a (hacky) function for moving clients to general
positions (eg, 2nd, 5th, etc) rather than just the `1st' that
zoom provides I don't feel the need to start the layout in
middle of screen, so that complexity goes away.

As ususal, patchDoc.txt contains brief description.

cheers, dave tweed