create the new FileServer and HandleDir, deprecate the rest APIBuilder/Party static methods and more

relative: https://github.com/kataras/iris/issues/1283 and removing pongo2 from vendor: https://github.com/kataras/iris/issues/1284

Former-commit-id: 3ec57b349f99faca2b8e36d9f7252db0b6ea080d

core/router/handler.go

@@ -76,11 +76,14 @@ func NewDefaultHandler() RequestHandler {
 type RoutesProvider interface { // api builder
 	GetRoutes() []*Route
 	GetRoute(routeName string) *Route
+	// GetStaticSites() []*StaticSite
+	// Macros() *macro.Macros
 }
 
 func (h *routerHandler) Build(provider RoutesProvider) error {
-	registeredRoutes := provider.GetRoutes()
 	h.trees = h.trees[0:0] // reset, inneed when rebuilding.
+	rp := errors.NewReporter()
+	registeredRoutes := provider.GetRoutes()
 
 	// sort, subdomains go first.
 	sort.Slice(registeredRoutes, func(i, j int) bool {
@@ -111,11 +114,8 @@ func (h *routerHandler) Build(provider RoutesProvider) error {
 
 		// the rest are handled inside the node
 		return lsub1 > lsub2
-
 	})
 
-	rp := errors.NewReporter()
-
 	for _, r := range registeredRoutes {
 		// build the r.Handlers based on begin and done handlers, if any.
 		r.BuildHandlers()
@@ -133,6 +133,7 @@ func (h *routerHandler) Build(provider RoutesProvider) error {
 			rp.Add("%v -> %s", err, r.String())
 			continue
 		}
+
 		golog.Debugf(r.Trace())
 	}