PLT-4357 adding performance monitoring (#4622)

* WIP

* WIP

* Adding metrics collection

* updating vendor packages

* Adding metrics to config

* Adding admin console page for perf monitoring

* Updating glide

* switching to tylerb/graceful

i18n/en.json

@@ -2659,6 +2659,14 @@
     "id": "ent.cluster.save_config.error",
     "translation": "System Console is set to read-only when High Availability is enabled."
   },
+  {
+    "id": "ent.metrics.starting.info",
+    "translation": "Metrics and profiling server is listening on %v"
+  },
+  {
+    "id": "ent.metrics.stopping.info",
+    "translation": "Metrics and profiling server is stopping on %v"
+  },
   {
     "id": "ent.cluster.starting.info",
     "translation": "Cluster internode communication is listening on %v with hostname=%v id=%v"