Update Polymer to 1.9.1. Use suppressBindingNotifications for perf

bower.json

@@ -24,7 +24,7 @@
   },
   "dependencies": {
     "app-layout": "PolymerElements/app-layout#^0.10.0",
-    "polymer": "Polymer/polymer#^1.8.1",
+    "polymer": "Polymer/polymer#^1.9.1",
     "google-apis": "GoogleWebComponents/google-apis#^1.0.2",
     "paper-listbox": "PolymerElements/paper-listbox#^1.1.2",
     "paper-item": "PolymerElements/paper-item#^1.0.3",

templates/base.html

@@ -60,6 +60,7 @@ window.Polymer = window.Polymer || {
   lazyRegister: 'max',
   useNativeCSSProperties: true,
   suppressTemplateNotifications: true, // Don't fire dom-change on dom-if, dom-bind, etc.
+  suppressBindingNotifications: true
   // disableUpgradeEnabled: true // Works with `disable-upgrade` attr. When removed, upgrades element.
 };