Detect X autostart a bit better with a separate service. The service
relies on a shell script which searches for a socket which X creates on
startup and only finishes when it finds the socket succesfully.
This makes services which need X to start successfully a bit more
robust, and while it can still break if X takes too long, it should be
more stable now.
Finally, services can restart more quickly when ended since they don't
require the 2+ `RestartSec` option to be present anymore to successfully
start.
Both greenclip and redshift did not automatically start on system start,
since they needed X to be running but their restart was almost
instantaneously. So, they restarted their alloted 5 times before X was
ready and gave up.
Restart time has been set to 5 and 10 seconds, so their startup takes a
little longer but should, in most cases, succeed.
