Changed the keepChannel to buffered channel.

Since the keepChannel is used to send data, not just for synchronizaiton,
so make it a buffered channel can avoid unnecessary goroutine yields.
Merge pull request #445 from yifan-gu/buffered_chan

Changed the keepChannel to buffered channel.
adding firewall instructions to the README
Merge pull request #447 from juliaferraioli/master

Add firewall instructions to the update demo
Add link env vars.
Merge pull request #440 from brendandburns/link

Add Docker link style env vars to link containers to services.
Update services to use the internal IP and port, now that its available.
Add a /healthz handler to the kubelet server, so that the master can validate kubelet health.
Address comments.
Merge pull request #419 from brendandburns/health

Add a /healthz handler to the kubelet server
Add a template printer to kubecfg.
Merge pull request #433 from brendandburns/service

Update services to use the internal IP and port, now that its available.
Move guestbook.md to README.md for default display by github.
Address comments.
Merge pull request #455 from brendandburns/readme

Move guestbook.md to README.md for default display by github.
Merge pull request #454 from brendandburns/template

Add a template printer to kubecfg.
Changed op.notify<-true to close(op.notify).