the repo to cope with the client repo staging area; added symlink vendor/k8s.io/client-go which pointed to the staging area.
This forces a regeneration if the generation tools are rebuilt. Also clean up Makefile a bit.
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.