Allow 40autorandr to handle any order fields from loginctl

Allow 40autorandr to handle any order fields from loginctl

This could be done a great deal more cleanly using bash regex matching;
however, as is stated elsewhere, the script will not always be executed
with bash.

There may be some merit to causing the script to always be executed with
bash (`#! /bin/bash` or even `#! /usr/bin/env bash`), but I'll admit I
don't know how widely installed bash is. I've certainly never found a
modern Linux install without bash, but my experience isn't the widest.