Automatic merge from submit-queue (batch tested with PRs 44222, 44614, 44292, 44638)

Smarter generic getters and describers

Makes printers and describers smarter for generic resources.

This traverses unstructured objects and prints their attributes for generic resources (TPR, federated API, etc) in `kubectl get` and `kubectl describe`. Makes use of the object's field names to come up with a best guess for describer labels and get headers, and field value types to understand how to better print it, indent, etc.

A nice intermediate solution while we don't have [get and describe extensions](https://github.com/kubernetes/community/pull/308).

Examples:

```
$ kubectl get serviceclasses
NAME                    KIND                                          BINDABLE   BROKER NAME   OSB GUID
user-provided-service   ServiceClass.v1alpha1.servicecatalog.k8s.io   false      ups-broker    4f6e6cf6-ffdd-425f-a2c7-3c9258ad2468
```

```
$ kubectl describe serviceclasses/user-provided-service
Name:		user-provided-service
Namespace:	
Labels:		<none>
Annotations:	FOO=BAR
		openshift.io/deployment.phase=test
OSB Metadata:	<nil>
Kind:		ServiceClass
Metadata:
  Self Link:		/apis/servicecatalog.k8s.io/v1alpha1/serviceclassesuser-provided-service
  UID:			1509bd96-1b05-11e7-98bd-0242ac110006
  Resource Version:	256
  Creation Timestamp:	2017-04-06T20:10:29Z
Broker Name:		ups-broker
Bindable:		false
Plan Updatable:		false
OSB GUID:		4f6e6cf6-ffdd-425f-a2c7-3c9258ad2468
API Version:		servicecatalog.k8s.io/v1alpha1
Plans:
  Name:		default
  OSB GUID:	86064792-7ea2-467b-af93-ac9694d96d52
  OSB Free:	true
  OSB Metadata:	<nil>
Events:		<none>
```

**Release note**:
```release-note
Improved output on 'kubectl get' and 'kubectl describe' for generic objects.
```
PTAL @pmorie @pwittrock @kubernetes/sig-cli-pr-reviews