Move network types to types package

This is need to decouple types from netutils which has linux
dependencies. This way the client code which needs network types
can just pull in types package which makes client code platform
agnostic.

Signed-off-by: Jana Radhakrishnan <mrjana@docker.com>

cmd/readme_test/readme.go

@@ -5,8 +5,8 @@ import (
 
 	"github.com/docker/libnetwork"
 	"github.com/docker/libnetwork/netlabel"
-	"github.com/docker/libnetwork/netutils"
 	"github.com/docker/libnetwork/options"
+	"github.com/docker/libnetwork/types"
 )
 
 func main() {
@@ -58,7 +58,7 @@ func main() {
 	epInfo, err := ep.DriverInfo()
 	mapData, ok := epInfo[netlabel.PortMap]
 	if ok {
-		portMapping, ok := mapData.([]netutils.PortBinding)
+		portMapping, ok := mapData.([]types.PortBinding)
 		if ok {
 			fmt.Printf("Current port mapping for endpoint %s: %v", ep.Name(), portMapping)
 		}