Use a vendor directory for repeatable builds - fixes #816

This is using godep to manage the vendor directory.

vendor/github.com/skratchdot/open-golang/open/exec_windows.go

@@ -0,0 +1,28 @@
+// +build windows
+
+package open
+
+import (
+	"os"
+	"os/exec"
+	"path/filepath"
+	"strings"
+)
+
+var (
+	cmd      = "url.dll,FileProtocolHandler"
+	runDll32 = filepath.Join(os.Getenv("SYSTEMROOT"), "System32", "rundll32.exe")
+)
+
+func cleaninput(input string) string {
+	r := strings.NewReplacer("&", "^&")
+	return r.Replace(input)
+}
+
+func open(input string) *exec.Cmd {
+	return exec.Command(runDll32, cmd, input)
+}
+
+func openWith(input string, appName string) *exec.Cmd {
+	return exec.Command("cmd", "/C", "start", "", appName, cleaninput(input))
+}