special thanks to Stephan for the configuration part

It turns out this new idea of mapping xinerama screens, and xrandr
monitors into a flat integer space is nice, but when we confuse
xrandr monitor 2 (idx 1) with X screen 1 (there is only one screen)
we bit the dust.

Many thanks to Cor Nouws for remote debugging assistance

Apparently the peculiarity that a non-existent file is newer than an
existing file is in GNU make 3.82, but not 3.81.

This should fix the bug, probably introduced with the per-directory
performance enhancements, that after a change to an IDL file 2 builds
are required to rebuild everything.

See also: 5513e24e

Part XXXVIII
Modules
svx