Use file tags to generate deep-copies

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).

pkg/api/doc.go

@@ -14,6 +14,8 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */
 
+// +k8s:deepcopy-gen=register
+
 // Package api contains the latest (or "internal") version of the
 // Kubernetes API objects. This is the API objects as represented in memory.
 // The contract presented to clients is located in the versioned packages,