Add notification at info-bar, and fix bug in visiting register/login page when user is already logged in.

notifications/utils.py

@@ -0,0 +1,11 @@
+from django.core.cache import cache
+
+from seahub.notifications.models import Notification
+
+def refresh_cache():
+    """
+    Function to be called when change primary notification.
+    """
+    cache.set('CUR_TOPINFO', Notification.objects.all().filter(primary=1),
+              24*60*60)
+