Use the built-in json module

Python >= 2.6 comes with json by default. simplejson is only useful for Python
<= 2.5.

seahub/views/ajax.py

@@ -2,7 +2,7 @@
 import os
 import stat
 import logging
-import simplejson as json
+import json
 
 from django.core.urlresolvers import reverse
 from django.http import HttpResponse, Http404, HttpResponseBadRequest