This drives most of the logic of deep-copy generation from tags like:
// +deepcopy-gen=package
..rather than hardcoded lists of packages. This will make it possible to
subsequently generate code ONLY for packages that need it *right now*, rather
than all of them always.
Also remove pkgs that really do not need deep-copies (no symbols used
anywhere).
His PR cam during the middle of this development cycle, and it was easier to
burn it down and recreate it than try to patch it into an existing series and
re-test every assumption. This behavior will be re-introduced in subsequent
commits.
