Windows: Updates Windows Vendoring

Updates windows dependent libraries for vendoing.

vendor/github.com/Microsoft/hcsshim/cmd/wclayer/import.go

@@ -0,0 +1,74 @@
+package main
+
+import (
+	"bufio"
+	"compress/gzip"
+	"io"
+	"os"
+	"path/filepath"
+
+	"github.com/Microsoft/go-winio"
+	"github.com/Microsoft/hcsshim/internal/appargs"
+	"github.com/Microsoft/hcsshim/internal/ociwclayer"
+	"github.com/urfave/cli"
+)
+
+var importCommand = cli.Command{
+	Name:  "import",
+	Usage: "imports a layer from a tar file",
+	Flags: []cli.Flag{
+		cli.StringSliceFlag{
+			Name:  "layer, l",
+			Usage: "paths to the read-only parent layers",
+		},
+		cli.StringFlag{
+			Name:  "input, i",
+			Usage: "input layer tar (defaults to stdin)",
+		},
+	},
+	ArgsUsage: "<layer path>",
+	Before:    appargs.Validate(appargs.NonEmptyString),
+	Action: func(context *cli.Context) (err error) {
+		path, err := filepath.Abs(context.Args().First())
+		if err != nil {
+			return err
+		}
+
+		layers, err := normalizeLayers(context.StringSlice("layer"), false)
+		if err != nil {
+			return err
+		}
+
+		fp := context.String("input")
+		f := os.Stdin
+		if fp != "" {
+			f, err = os.Open(fp)
+			if err != nil {
+				return err
+			}
+			defer f.Close()
+		}
+		r, err := addDecompressor(f)
+		if err != nil {
+			return err
+		}
+		err = winio.EnableProcessPrivileges([]string{winio.SeBackupPrivilege, winio.SeRestorePrivilege})
+		if err != nil {
+			return err
+		}
+		_, err = ociwclayer.ImportLayer(r, path, layers)
+		return err
+	},
+}
+
+func addDecompressor(r io.Reader) (io.Reader, error) {
+	b := bufio.NewReader(r)
+	hdr, err := b.Peek(3)
+	if err != nil {
+		return nil, err
+	}
+	if hdr[0] == 0x1f && hdr[1] == 0x8b && hdr[2] == 8 {
+		return gzip.NewReader(b)
+	}
+	return b, nil
+}