Automatic merge from submit-queue (batch tested with PRs 40645, 40541, 40769)
Fix sorting printer when sorting by a missing field
**What this PR does / why we need it**:
When calling `kubectl get` with the `--sort-by` flag, the command will error out if the field used for sorting is not present in at least one of the objects returned in the list, *even if it is a field valid in the object's model*.
For example, taking a list of `ReplicationController` where one of them has `status: { replicas: 0 }` (so nothing in `status.availableReplicas`, even that being a valid object in the model and present in every other object of the list) :
```
$ oc get rc --sort-by=status.availableReplicas
error: availableReplicas is not found
```
This PR now traverses the entire list of objects to be sorted and, if at least one has the field provided in `--sort-by`, we sort correctly and consider the field empty in every other object where the field is not present. If none of the objects has the field, we error out (that will catch really invalid fields, and valid ones but not present in any object in the list, which is acceptable). No swagger validation here.
**Release note**:
```release-note
Fixed an issue where 'kubectl get --sort-by=' would return an error when the specified field were not present in at least one of the returned objects, even that being a valid field in the object model.
```
Automatic merge from submit-queue (batch tested with PRs 38592, 39949, 39946, 39882)
move api/errors to apimachinery
`pkg/api/errors` is a set of helpers around `meta/v1.Status` that help to create and interpret various apiserver errors. Things like `.NewNotFound` and `IsNotFound` pairings. This pull moves it into apimachinery for use by the clients and servers.
@smarterclayton @lavalamp First commit is the move plus minor fitting. Second commit is straight replace and generation.
The kubectl version output is very complex and makes it hard for users
and vendors to give actionable information. For example during the
recent Kubernetes 1.4.3 TLS security scramble I had to write a one-liner
for users to get out the version number to give to figure out if they
are vulnerable:
$ kubectl version | grep -i Server | sed -n 's%.*GitVersion:"\([^"]*\).*%\1%p'
Instead this patch outputs simply output with `--short`
./kubectl version --short
Client Version: v1.4.3
Server Version: v1.4.3
Automatic merge from submit-queue
Verify and update client-go staging area for every PR
We need to keep the staging area up-to-date to prevent PRs from breaking client-go.
It's marked as "WIP" because we need to decide the [versioning strategy](https://github.com/kubernetes/client-go/issues/9) for client-go first. This PR contains breaking changes for client-go.
This is blocking #29934 and potentially #34441
cc @kubernetes/sig-api-machinery
