update code.goole.com/p/go.net to golang.org/x/net

https://groups.google.com/forum/#!topic/golang-nuts/eD8dh3T9yyA
Allow proxy to run on systems with iptables <1.4.11
Update go-restful to get field description enhancement and anonymous struct fix.
Update changelog for 0.5
Kubelet talks securely to apiserver.

Configure apiserver to serve Securely on port 6443.
Generate token for kubelets during master VM startup.
Put token into file apiserver can get and another file the kubelets can get.
Added e2e test.
Don't reference non-existent token file if not GCE.
Only test events on GCE.
Merge pull request #2432 from bgrant0607/docgen

Update go-restful to get field description enhancement and anonymous struct fix
Merge pull request #2387 from erictune/secure_port_on

Kubelet talks securely to apiserver
Merge pull request #2067 from hmrm/iptables-compatibility

Remove iptables >1.4.11 specific functionality
Add descriptions to all v1beta1 API fields.
Merge pull request #2187 from eparis/go.net-rename

update code.goole.com/p/go.net to golang.org/x/net
Treat unset KUBERNETES_PROVIDER as gce.

Should fix jenkins failure.
Merge pull request #2434 from brendandburns/release

Update changelog for 0.5
Merge pull request #2444 from bgrant0607/docfix

Add descriptions to all v1beta1 API fields.
Merge pull request #2446 from erictune/secure_port_on

Treat unset KUBERNETES_PROVIDER as gce.