Merge branch 'v0.4' of github.com:hmarr/mongoengine into v0.4

mongoengine/base.py

@@ -255,6 +255,7 @@ class TopLevelDocumentMetaclass(DocumentMetaclass):
             'index_background': False,
             'index_drop_dups': False,
             'index_opts': {},
+            'queryset_class': QuerySet,
         }
         meta.update(base_meta)
 

mongoengine/queryset.py

@@ -999,7 +999,8 @@ class QuerySetManager(object):
                 self._collection = db[collection]
 
         # owner is the document that contains the QuerySetManager
-        queryset = QuerySet(owner, self._collection)
+        queryset_class = owner._meta['queryset_class'] or QuerySet
+        queryset = queryset_class(owner, self._collection)
         if self._manager_func:
             if self._manager_func.func_code.co_argcount == 1:
                 queryset = self._manager_func(queryset)