Add notifications control.

Experimental. Pushes updates of interest (currently
new / changed log entries) via the Notifications API.
Can be enabled or disabled by the user at any time.

lib/www/client/source/src/components/footer.vue

@@ -9,6 +9,8 @@
 
 	<v-spacer></v-spacer>
 
+	<dougal-notifications-control class="mr-6"></dougal-notifications-control>
+
 	<div title="Night mode">
       <v-switch
         class="ma-auto"
@@ -35,12 +37,14 @@
 <script>
 
 import DougalHelpDialog from '@/components/help-dialog';
+import DougalNotificationsControl from '@/components/notifications-control';
 
 export default {
   name: 'DougalFooter',
 
   components: {
-    DougalHelpDialog
+    DougalHelpDialog,
+    DougalNotificationsControl
   },
 
   computed: {