Move from glog to klog

- Move from the old github.com/golang/glog to k8s.io/klog
- klog as explicit InitFlags() so we add them as necessary
- we update the other repositories that we vendor that made a similar
change from glog to klog
  * github.com/kubernetes/repo-infra
  * k8s.io/gengo/
  * k8s.io/kube-openapi/
  * github.com/google/cadvisor
- Entirely remove all references to glog
- Fix some tests by explicit InitFlags in their init() methods

Change-Id: I92db545ff36fcec83afe98f550c9e630098b3135

pkg/volume/flexvolume/unmounter-defaults.go

@@ -17,13 +17,13 @@ limitations under the License.
 package flexvolume
 
 import (
-	"github.com/golang/glog"
+	"k8s.io/klog"
 	"k8s.io/kubernetes/pkg/volume/util"
 )
 
 type unmounterDefaults flexVolumeUnmounter
 
 func (f *unmounterDefaults) TearDownAt(dir string) error {
-	glog.Warning(logPrefix(f.plugin), "using default TearDownAt for ", dir)
+	klog.Warning(logPrefix(f.plugin), "using default TearDownAt for ", dir)
 	return util.UnmountPath(dir, f.mounter)
 }