turn webpack middleware into middleware

fix HMR middleware, and some loopback boilerplate cleanup

server/middleware.development.json

@@ -1,4 +1,12 @@
 {
+  "routes:before": {
+    "./middleware/webpack-dev": {
+      "params": { "enabled": true }
+    },
+    "./middleware/webpack-hmr": {
+      "params": { "enabled": true }
+    }
+  },
   "final:after": {
     "strong-error-handler": {
       "params": {