Automatic merge from submit-queue
Make kubectl bash-completion namespace and resource alias aware
- filter resource listing by `--namespace` flag given before in the command line
```bash
$ kubectl get pod --namespace=kube-system <tab><tab>
kube-dns-v9-2wuzj kube-dns-v9-llqxa
```
- add completion of `--namespace`
```bash
$ kubectl get pod --namespace=<tab><tab>
[*] default ingress kube-system
```
- add support for plural nouns and aliases like `rc`
e121b562c5
