This means the kernel now depends on libj6. I've added the macro
definition __j6kernel when building for the kernel target, so I can
remove parts with #ifdefs.
Overall, I believe TOML to be a superior configuration format than YAML
in many situations, but it gets ugly quickly when nesting data
structures. The build configs were fine in TOML, but the manifest (and
my future plans for it) got unwieldy. I also did not want different
formats for each kind of configuration on top of also having a custom
DSL for interface definitions, so I've switched all the TOML to YAML.
Also of note is that this change actually adds structure to the manifest
file, which was little more than a CSV previously.
