Defaults for Podman that were previous applied as command-line arguments
to all `podman run` or `podman create` invocations are now specified in
a dedicated configuration file.
Services are also better identified against their name rather than the
generic `podman` ID derived from the `ExecStart` invocations.
This commit represents a large amount of work toward moving services to
a more standard approach to storing data, and a simplification in how
networks are managed.
This contains the culmination of work done privately for a few months,
and is intended to be a solid basis for other peoples' experimentations
with setting up single-node, home-server setups using Fedora CoreOS.