adds vendor directory

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

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

@@ -0,0 +1,40 @@
+package main
+
+import (
+	"os"
+	"unsafe"
+
+	"github.com/mattn/go-gtk/gdkpixbuf"
+	"github.com/mattn/go-gtk/glib"
+	"github.com/mattn/go-gtk/gtk"
+)
+
+func main() {
+	gtk.Init(&os.Args)
+	window := gtk.NewWindow(gtk.WINDOW_TOPLEVEL)
+	window.SetTitle("GTK Icon View")
+	window.Connect("destroy", gtk.MainQuit)
+
+	swin := gtk.NewScrolledWindow(nil, nil)
+
+	store := gtk.NewListStore(gdkpixbuf.GetType(), glib.G_TYPE_STRING)
+	iconview := gtk.NewIconViewWithModel(store)
+	iconview.SetPixbufColumn(0)
+	iconview.SetTextColumn(1)
+	swin.Add(iconview)
+
+	gtk.StockListIDs().ForEach(func(d unsafe.Pointer, v interface{}) {
+		id := glib.GPtrToString(d)
+		var iter gtk.TreeIter
+		store.Append(&iter)
+		store.Set(&iter,
+			0, gtk.NewImage().RenderIcon(id, gtk.ICON_SIZE_SMALL_TOOLBAR, "").GPixbuf,
+			1, id)
+	})
+
+	window.Add(swin)
+	window.SetSizeRequest(500, 200)
+	window.ShowAll()
+
+	gtk.Main()
+}