Updating handleIndex in master to list all valid paths.

The list of valid paths is computed from http.ServeMux and
restful.WebService.
Adding a mux helper - wrapper over mux, that keeps track of the paths
handled by mux.

pkg/apiserver/mux_helper.go

@@ -0,0 +1,37 @@
+/*
+Copyright 2015 Google Inc. All rights reserved.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package apiserver
+
+import (
+	"net/http"
+)
+
+// Offers additional functionality over ServeMux, for ex: supports listing registered paths.
+type MuxHelper struct {
+	Mux             Mux
+	RegisteredPaths []string
+}
+
+func (m *MuxHelper) Handle(path string, handler http.Handler) {
+	m.RegisteredPaths = append(m.RegisteredPaths, path)
+	m.Mux.Handle(path, handler)
+}
+
+func (m *MuxHelper) HandleFunc(path string, handler func(http.ResponseWriter, *http.Request)) {
+	m.RegisteredPaths = append(m.RegisteredPaths, path)
+	m.Mux.HandleFunc(path, handler)
+}