Merge branch 'master' of https://github.com/kubernetes/website into release-1.9

* 'master' of https://github.com/kubernetes/website: (140 commits)
  Update configure-multiple-schedulers.md (#6877)
  Explicitly specify the components that need a change (#6873)
  Updates to partner page (#6797)
  Add steps for extension api-server setup (#6667)
  securing a cluster: add recommendations about cloud metadata APIs (#6659)
  Namespace glossary term (#6607)
  Update device plugin doc with upgrade suggestions and known limitations. (#6501)
  Add Kubermatic to pick-right-solution.md (#6459)
  extra word
  typo
  Fix concepts/configuration/secret
  Link to extended resources instead of deprecated opaque integer resources
  Fix CI issue
  Corrected the group in runtime-config of ValidatingAdmissionWebhook and MutatingAdmissionWebhook. It should be admissionregistration.k8s.io (was admissionregistration).
  Correct references in Jekyll data files
  Update scheduling-hugepages.md
  Drop reference to outdated FAQ
  Follow sig list to kubernetes/community
  Update scheduling-hugepages.md
  Fix references to ConfigMap for the CN website
  ...

# Conflicts:
#	docs/concepts/policy/pod-security-policy.md

docs/tutorials/stateful-application/webp.yaml

@@ -31,7 +31,7 @@ spec:
     spec:
       containers:
       - name: nginx
-        image: gcr.io/google_containers/nginx-slim:0.8
+        image: k8s.gcr.io/nginx-slim:0.8
         ports:
         - containerPort: 80
           name: web