Reasoning: Since 2011 dmenu has been capable of working out which
monitor currently has focus in a Xinerama setup, making the use
of the -m flag more or less redundant.

This is easily demonstrated by using dmenu in any other window
manager.

There used to be a nodmenu patch that provided these changes:
https://git.suckless.org/sites/commit/ed68e3629de4ef2ca2d3f8893a79fb570b4c0cbc.html

but this was removed on the basis that it was very easy to work
out and apply manually if needed.

The proposal here is to remove this dependency from dwm. The
mechanism of the dmenumon variable could be provided via a patch
if need be.

The edge case scenario that dmenu does not handle on its own, and
the effect of removing this mechanism, is that if the user trigger
focusmon via keybindings to change focus to another monitor that
has no clients, then dmenu will open on the monitor containing the
window with input focus (or the monitor with the mouse cursor if
no windows have input focus).

If this edge case is important to cover then this can be addressed
by setting input focus to selmon->barwin in the focus function if
there is no client to give focus to (rather than giving focus back
to the root window).

pretty much all other variables are declared as const when they're not
modified.

Some people are annoyed to have this new behaviour forced for some
application which use fake fullscreen.

by Christopher Drelich <cd@cdrakka.com>

Patch was mangled on the ML, also adjusted the order to be the same as
the enum in dwm.c

- unify multi-line expression alignment style.
- unify multi-line function call alignment style.
- simplify client moving on monitor count decrease.
- clarify comment for focusin().
- remove old confusing comment about input focus fix in focusmon(). The
  explanation is already in the old commit message, so no need to keep it in the
  code.
- remove old comment describing even older state of the code in focus().
- unify comment style.
- break up some long lines.
- fix some typos and grammar.

- better scaling for occupied tag squares.
- draw statusline first to omitt some complicated calculations.

True, False are X11-specific (int), make sure to use c99 stdbool for
program-specific things.

dmenu uses Xft now (soon to be released).