This mostly takes the previously checked in files and removes them, and moves
the generation to be on-demand instead of manual. Manually verified no change
in generated output.
This allows us to start building real dependencies into Makefile.
Leave old hack/* scripts in place but advise to use 'make'. There are a few
rules that call things like 'go run' or 'build/*' that I left as-is for now.
This drives conversion generation from file tags like:
// +conversion-gen=k8s.io/my/internal/version
.. rather than hardcoded lists of packages.
The only net change in generated code can be explained as correct. Previously
it didn't know that conversion was available.
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).
