Properly localize group changes (#1802)

* Properly localize group updates

* Remove phone number in display name if contact in address book

* New string for multiple new group members

js/models/conversations.js

@@ -1017,6 +1017,24 @@
         }
     },
 
+    getDisplayName: function() {
+        if (!this.isPrivate()) {
+            return this.getTitle();
+        }
+
+        var name = this.get('name');
+        if (name) {
+            return name;
+        }
+
+        var profileName = this.get('profileName');
+        if (profileName) {
+            return this.getNumber() + ' ~' + profileName;
+        }
+
+        return this.getNumber();
+    },
+
     getNumber: function() {
         if (!this.isPrivate()) {
             return '';