dashboard next: minor improvements

* rename route to dashboard-next
* better scaling of charts for large data sets
* adjust trend position to avoid overlap
* makes sure silenced/suspended is made on real users
* correctly format data when only one data point
* minor refactoring

app/assets/javascripts/admin/controllers/admin-dashboard-next.js.es6

@@ -41,6 +41,6 @@ export default Ember.Controller.extend({
   },
 
   _reportsForPeriodURL(period) {
-    return `/admin/dashboard_next?period=${period}`;
+    return `/admin/dashboard-next?period=${period}`;
   }
 });