Log Message:
Maintainer update to dwm-5.7.2.

5.7.2 changes:
 o another fix for setlayout from Ryan Zheng
5.7.1 changes:
 o fixes layout symbol updating mechanism during setlayout
5.7 changes:
 o code cleanups and several minor improvements
 o layout symbol can be modified by the arrange function of a layout
 o new updategeom() algorithm rewritten from scratch