Vendor containers/storage, update containers/image

Vendor containers/storage, and its dependencies github.com/pborman/uuid
and github.com/mistifyio/go-zfs, which we didn't already use.

Update the build Dockerfile to install their dependencies.

Add scriptlets that try to detect whether or not we need to use the
"libdm_no_deferred_remove" and/or "btrfs_noversion" build tags.

Signed-off-by: Nalin Dahyabhai <nalin@redhat.com>

vendor/github.com/containers/storage/drivers/aufs/mount.go

@@ -0,0 +1,21 @@
+// +build linux
+
+package aufs
+
+import (
+	"os/exec"
+	"syscall"
+
+	"github.com/Sirupsen/logrus"
+)
+
+// Unmount the target specified.
+func Unmount(target string) error {
+	if err := exec.Command("auplink", target, "flush").Run(); err != nil {
+		logrus.Warnf("Couldn't run auplink before unmount %s: %s", target, err)
+	}
+	if err := syscall.Unmount(target, 0); err != nil {
+		return err
+	}
+	return nil
+}