Add a isNicklistEmpty method to buffer model, speed up nicklist decision

Flattening the nicklist is really unnecessary. This method is 10x faster for short
nicklists, and much faster for buffers with lots of users.

js/glowingbear.js

@@ -975,8 +975,8 @@ weechat.controller('WeechatCtrl', ['$rootScope', '$scope', '$store', '$timeout',
         if ($scope.nonicklist) {
             return false;
         }
-        // Use flat nicklist to check if empty
+        // Check if nicklist is empty
-        if (ab.flatNicklist().length === 0) {
+        if (ab.isNicklistEmpty()) {
             return false;
         }
         return true;

js/models.js

@@ -147,6 +147,13 @@ models.service('models', ['$rootScope', '$filter', function($rootScope, $filter)
             }
         };
 
+        var isNicklistEmpty = function() {
+            for (var obj in nicklist) {
+                return false;
+            }
+            return true;
+        };
+
         return {
             id: pointer,
             fullName: fullName,
@@ -171,7 +178,8 @@ models.service('models', ['$rootScope', '$filter', function($rootScope, $filter)
             history: history,
             addToHistory: addToHistory,
             getHistoryUp: getHistoryUp,
-            getHistoryDown: getHistoryDown
+            getHistoryDown: getHistoryDown,
+            isNicklistEmpty: isNicklistEmpty
         };
 
     };