They're almost entirely autogenerated, and we use symlinks into the
top directory to reduce replication.
They can't be under pyln.spec.message, because a package can't also
be a namespace.
We also add fulltext and desc fields, and exclude our "gen" files from
flake8, since the spec quotes contain weird whitespace.
Changelog-Added: Python: pyln.spec.bolt{1,2,4,7} packages.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
