[dev] dwm: Dynamic tag names patch

This patch allows you to dynamically change the names of tags in dwm.
This is implemented via a new command system that reads changes to the
DWM_COMMAND property of the root window. The format of this property is
a single letter command followed directly by a string argument. The
only command currently recognised is N, which sets the name of all
currently selected tags to n(str) where n is the tag number, and str is
the argument to the command. I also wrote a little program to set a
named property of the root window (also attached). E.g.

xsetatom DWM_COMMAND Nmusic

will set the names of the selected tags to 'n(music)'.

A little dmenu script is handy for this.

New commands are easily implemented (see runcommand()). Patch is
against mercurial tip.

Apologies for the repeat, this is a fixed version of the patch I posted
on the XComposite thread (now tag numbers start at one).

Tom

-- 
Thomas Spurden