This also updates the Ignition compilation dependency resolution to
ignore local file references that have been commented out, and masks the
timer for updating CoreOS configuration in virtual environments, to
avoid overriding any changes made locally.
This partially reverts default network configuration, which will now
implicitly create the specified network without the ability to set
default plugins.
Templated services are also no longer enabled by default, but expect to
be enabled as part of concrete patterns.
And introduce a `purge` target, intended to supplant the current `clean`
target, in allowing the latter to be used to clean Butane configuration
without removing any cached images.
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.