Add browser cookie support for timezone middleware.

mayan/apps/common/middleware/timezone.py

@@ -2,17 +2,18 @@ from __future__ import unicode_literals
 
 import pytz
 
+from django.conf import settings
 from django.utils import timezone
 
 
 class TimezoneMiddleware(object):
     def process_request(self, request):
         if hasattr(request, 'session'):
-            tzname = request.session.get('django_timezone')
-            if tzname:
-                timezone.activate(pytz.timezone(tzname))
-            else:
-                timezone.deactivate()
+            tzname = request.session.get(settings.TIMEZONE_SESSION_KEY)
+        else:
+            tzname = HttpRequest.COOKIES.get(settings.TIMEZONE_COOKIE_NAME)
+
+        if tzname:
+            timezone.activate(pytz.timezone(tzname))
         else:
-            # TODO: Cookie, browser based timezone
             timezone.deactivate()