Windows Support

Patch for https://github.com/containernetworking/plugins/pull/85

+ Windows cni plugins are added
   (*) win-bridge (hostgw)
   (*) win-overlay (vxlan)
+ Windows netconf unit test
+ Fix appveyor config to run the test
+ Build release support for windows plugins

Address comments

From:
    - https://github.com/containernetworking/plugins/pull/85
    - 0049c64e3f

plugins/meta/flannel/flannel.go

@@ -42,6 +42,7 @@ const (
 
 type NetConf struct {
 	types.NetConf
+
 	SubnetFile string                 `json:"subnetFile"`
 	DataDir    string                 `json:"dataDir"`
 	Delegate   map[string]interface{} `json:"delegate"`
@@ -202,43 +203,7 @@ func cmdAdd(args *skel.CmdArgs) error {
 		}
 	}
 
-	n.Delegate["name"] = n.Name
-
-	if !hasKey(n.Delegate, "type") {
-		n.Delegate["type"] = "bridge"
-	}
-
-	if !hasKey(n.Delegate, "ipMasq") {
-		// if flannel is not doing ipmasq, we should
-		ipmasq := !*fenv.ipmasq
-		n.Delegate["ipMasq"] = ipmasq
-	}
-
-	if !hasKey(n.Delegate, "mtu") {
-		mtu := fenv.mtu
-		n.Delegate["mtu"] = mtu
-	}
-
-	if n.Delegate["type"].(string) == "bridge" {
-		if !hasKey(n.Delegate, "isGateway") {
-			n.Delegate["isGateway"] = true
-		}
-	}
-	if n.CNIVersion != "" {
-		n.Delegate["cniVersion"] = n.CNIVersion
-	}
-
-	n.Delegate["ipam"] = map[string]interface{}{
-		"type":   "host-local",
-		"subnet": fenv.sn.String(),
-		"routes": []types.Route{
-			types.Route{
-				Dst: *fenv.nw,
-			},
-		},
-	}
-
-	return delegateAdd(args.ContainerID, n.DataDir, n.Delegate)
+	return doCmdAdd(args, n, fenv)
 }
 
 func cmdDel(args *skel.CmdArgs) error {
@@ -247,25 +212,10 @@ func cmdDel(args *skel.CmdArgs) error {
 		return err
 	}
 
-	netconfBytes, err := consumeScratchNetConf(args.ContainerID, nc.DataDir)
-	if err != nil {
-		if os.IsNotExist(err) {
-			// Per spec should ignore error if resources are missing / already removed
-			return nil
-		}
-		return err
-	}
-
-	n := &types.NetConf{}
-	if err = json.Unmarshal(netconfBytes, n); err != nil {
-		return fmt.Errorf("failed to parse netconf: %v", err)
-	}
-
-	return invoke.DelegateDel(n.Type, netconfBytes, nil)
+	return doCmdDel(args, nc)
 }
 
 func main() {
-	// TODO: implement plugin version
 	skel.PluginMain(cmdAdd, cmdGet, cmdDel, version.All, "TODO")
 }