Automatic merge from submit-queue

log info on invalid --output-version

**Release note**:

``` release-note
release-note-none
```

Object versions default to the current version (v1) when a specified
`--output-version` is invalid. This patch logs a warning when this is
the case. Cases affected are all commands with the `--output-version`
option, and anywhere runtime objects are converted to versioned objects.

**Example**

```
$ kubectl get pod <mypod> -o json --output-version=invalid
W1013 17:24:16.810278   26719 result.go:238]  info: the output version
specified (invalid) is invalid, defaulting to v1
{
        "kind": "Pod",
            "apiVersion": "v1",
                "metadata": {
                            "name": "mypod",
                                    "namespace": "test",
...
```