Move archive package into pkg/archive

Now that the archive package does not depend on any docker-specific
packages, only those in pkg and vendor, it can be safely moved into pkg.

Signed-off-by: Rafe Colton <rafael.colton@gmail.com>

archive/time_linux.go

@@ -0,0 +1,16 @@
+package archive
+
+import (
+	"syscall"
+	"time"
+)
+
+func timeToTimespec(time time.Time) (ts syscall.Timespec) {
+	if time.IsZero() {
+		// Return UTIME_OMIT special value
+		ts.Sec = 0
+		ts.Nsec = ((1 << 30) - 2)
+		return
+	}
+	return syscall.NsecToTimespec(time.UnixNano())
+}