Use apiserver instead of etcd for kube-proxy.

For cloud-providers that use salt, have kube-proxy use
apiserver instead of etcd as a config source.
- make cadvisor port configurable on the kubelet.
- added cadvisor port documentation.
Added two test cases for KubeletClient
Update roadmap based on discussion at contributor meetup.
Scheduler changes for extensibility
Scheduler changes to allow multiple priority functions
Fixing gofmt errors
Combining scheduler priority functions using weighted averages
Implementing PR feedback
 - Making ConfigFactory struct public
 - Added comments for predicate/priority functions and new methods
Implementing PR feedback and adding test cases
x509 request authenticator
Add network testing pod
Make guestbook handle duplicate entries.

Also use kubernetes org on the Docker Hub to host the image.

Fixes #2811
Revert "Revert "Add optional validation to kubecfg/kubectl.""

This reverts commit 6590c66dd47f6aee671687493700bcf038d89725.
Make validation optional, handle YAML
add network test to e2e.go
Merge pull request #2784 from bgrant0607/docfix

Update roadmap based on discussion at contributor meetup.
Merge pull request #2812 from jbeda/guestbook-dup-fix

Make guestbook handle duplicate entries.
Merge pull request #2621 from brendandburns/kubecfg

Add validation back in
Merge pull request #2793 from liggitt/tls_auth

x509 request authenticator