Merge branch 'dev' into hohoTT-dev

Conflicts:
	oj/settings.py
	oj/urls.py
	problem/views.py

oj/settings.py

@@ -39,7 +39,6 @@ ALLOWED_HOSTS = []
 # Application definition
 
 INSTALLED_APPS = (
-    'django.contrib.admin',
     'django.contrib.auth',
     'django.contrib.contenttypes',
     'django.contrib.sessions',
@@ -51,6 +50,7 @@ INSTALLED_APPS = (
     'utils',
     'group',
     'problem',
+    'admin',
 
     'rest_framework',
     'rest_framework_swagger',