adds vendor directory

vendors dependencies in standard `vendor` directory, managed by glide

vendor/github.com/mattn/go-gtk/example/arrow/arrow.go

@@ -0,0 +1,48 @@
+package main
+
+import (
+	"github.com/mattn/go-gtk/gtk"
+	"os"
+)
+
+func createArrowButton(at gtk.ArrowType, st gtk.ShadowType) *gtk.Button {
+	b := gtk.NewButton()
+	a := gtk.NewArrow(at, st)
+
+	b.Add(a)
+
+	b.Show()
+	a.Show()
+
+	return b
+}
+
+func main() {
+	gtk.Init(&os.Args)
+
+	window := gtk.NewWindow(gtk.WINDOW_TOPLEVEL)
+	window.SetTitle("Arrow Buttons")
+	window.Connect("destroy", gtk.MainQuit)
+
+	box := gtk.NewHBox(false, 0)
+	box.Show()
+	window.Add(box)
+
+	up := createArrowButton(gtk.ARROW_UP, gtk.SHADOW_IN)
+	down := createArrowButton(gtk.ARROW_DOWN, gtk.SHADOW_OUT)
+	left := createArrowButton(gtk.ARROW_LEFT, gtk.SHADOW_ETCHED_IN)
+	right := createArrowButton(gtk.ARROW_RIGHT, gtk.SHADOW_ETCHED_OUT)
+
+	box.PackStart(up, false, false, 3)
+	box.PackStart(down, false, false, 3)
+	box.PackStart(left, false, false, 3)
+	box.PackStart(right, false, false, 3)
+
+	up.Clicked(func() { println("↑") })
+	down.Clicked(func() { println("↓") })
+	left.Clicked(func() { println("←") })
+	right.Clicked(func() { println("→") })
+
+	window.Show()
+	gtk.Main()
+}