Cleanup non-rest apiserver handlers

- rename MuxHelper -> PathRecorderMux
- move non-rest handlers into routes packages within genericapiserver and
  `pkg/routes` (those from master)
- move ui and logs handlers out of genericapiserver (they are
  not generic)
- make version handler configurable (`config.EnableVersion`)

api/swagger-spec/resourceListing.json

@@ -1,10 +1,6 @@
 {
   "swaggerVersion": "1.2",
   "apis": [
-   {
-    "path": "/logs",
-    "description": "get log files"
-   },
    {
     "path": "/version",
     "description": "git code version from which this is built"
@@ -13,6 +9,10 @@
     "path": "/apis",
     "description": "get available API versions"
    },
+   {
+    "path": "/logs",
+    "description": "get log files"
+   },
    {
     "path": "/api/v1",
     "description": "API at /api/v1"