register libnetwork API and UI with docker parent chain

This commit also brings in the ability to specify a default network and its
corresponding driver as daemon flags. This helps in existing clients to
make use of newer networking features provided by libnetwork.

Signed-off-by: Madhu Venugopal <madhu@docker.com>

api/client/network.go

@@ -0,0 +1,15 @@
+// +build experimental
+
+package client
+
+import (
+	"os"
+
+	nwclient "github.com/docker/libnetwork/client"
+)
+
+func (cli *DockerCli) CmdNetwork(args ...string) error {
+	nCli := nwclient.NewNetworkCli(cli.out, cli.err, nwclient.CallFunc(cli.call))
+	args = append([]string{"network"}, args...)
+	return nCli.Cmd(os.Args[0], args...)
+}