Update vendor for Pug (Jade) Parser and add Iris + Pug examples in the _examples/view folder, relative to https://github.com/kataras/iris/issues/1003

Former-commit-id: e26a5701e00ec055f3bcf693c1980c7d22147310

_examples/view/template_pug_0/main.go

@@ -0,0 +1,29 @@
+package main
+
+import "github.com/kataras/iris"
+
+func main() {
+	app := iris.New()
+
+	tmpl := iris.Pug("./templates", ".pug")
+	tmpl.Reload(true)                             // reload templates on each request (development mode)
+	tmpl.AddFunc("greet", func(s string) string { // add your template func here.
+		return "Greetings " + s + "!"
+	})
+
+	app.RegisterView(tmpl)
+
+	app.Get("/", index)
+
+	// http://localhost:8080
+	app.Run(iris.Addr(":8080"))
+}
+
+func index(ctx iris.Context) {
+	ctx.ViewData("pageTitle", "My Index Page")
+	ctx.ViewData("youAreUsingJade", true)
+	// Q: why need extension .pug?
+	// A: Because you can register more than one view engine per Iris application.
+	ctx.View("index.pug")
+
+}

_examples/view/template_pug_0/templates/index.pug

@@ -0,0 +1,25 @@
+mixin withGo
+  | Generating Go html/template output.
+
+doctype html
+html(lang="en")
+  head
+    title= .pageTitle
+    script(type='text/javascript').
+      if (foo) {
+         bar(1 + 5)
+      }
+  body
+    h1 Jade - template engine
+    #container.col
+      if .youAreUsingJade
+        p {{ greet "iris user" }} <!-- execute template funcs -->
+        p You are amazing!
+      else
+        p Get on it!
+      p.
+        Jade is #[a(terse)] and simple
+        templating language with a
+        #[strong focus] on performance
+        and powerful features.
+      + withGo