Move Linux client & common packages into a public repo.

portlist/portlist_windows.go

@@ -0,0 +1,16 @@
+// Copyright (c) 2020 Tailscale Inc & AUTHORS All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package portlist
+
+// Forking on Windows is insanely expensive, so don't do it too often.
+const POLL_SECONDS = 5
+
+func listPorts() (List, error) {
+	return listPortsNetstat("-na")
+}
+
+func addProcesses(pl []Port) ([]Port, error) {
+	return listPortsNetstat("-nab")
+}