Add sysotad.conf configuration file
We want to read a configuration file, probably in the typical
/lib scheme that systemd is popularizing.
We want to have a way to pick the boot protocol backend, so that we can drop the pi boot hack needed for testing. The configuration file will also allow us to define the maker and model as well as the subscribed update stream.
The configuration file needs to be both human and machine readable. I'm somewhat inclined to extend the picfg parser to handle any ini-style files correctly, add support for perfect round trip to handle comments and use that as the basis for
sysotad.conf. I see the following reasons why this is useful:
- we can load .ini files from C or Go with great ease because that format is just very simple
- yaml is extremely complex and has poor security track record, in both library implementations and consequences of loading self-referential data structures into memory and handling them from there
- json is not human writable usually, lacking ability to store comments an needing pesky commas in just the right amount