We don't need two (and half) templating systems anymore, yay!
I'm keeping the changes minimal, to make the diff manageable. Some enhancements
due to a better templating system might be possible in the future.
For handling of '## ' — see the next commit.
RC_LOCAL_SCRIPT_PATH_START and RC_LOCAL_SCRIPT_PATH_STOP were was originally
added in the conversion to meson based on the autotools name. In
4450894653 RC_LOCAL_SCRIPT_PATH_STOP was dropped.
We don't need to use such a long name.
With the current "Type=forking", systemd tries to guess the PID it
should wait on at reboot (because we have no "PIDFile="). Depending on
how wrong the guess is, we can end up hanging forever at reboot.
Asking it not to do that eliminates the problem.
This also drops automatic selection of the rc local scripts
based on the local distro. Distributions now should specify the paths
of the rc-local and halt-local scripts on the configure command line.
