Fix compat for CPython/PyPy 2.x

__builtins__ should be accessed as a module, not a dict.

flask_admin/_compat.py

@@ -49,7 +49,7 @@ else:
         return unicode(s)
 
     # Helpers
-    reduce = __builtins__['reduce']
+    reduce = __builtins__.reduce
     from urlparse import urljoin