Fix two split mongo bugs that were causing problems...

common/lib/xmodule/xmodule/modulestore/split_mongo/mongo_connection.py

@@ -255,7 +255,7 @@ class MongoConnection(object):
         """
         Retrieve all definitions listed in `definitions`.
         """
-        return self.definitions.find({'$in': {'_id': definitions}})
+        return self.definitions.find({'_id': {'$in': definitions}})
 
     def insert_definition(self, definition):
         """

common/lib/xmodule/xmodule/modulestore/split_mongo/split.py

@@ -673,7 +673,7 @@ class SplitMongoModuleStore(SplitBulkWriteMixin, ModuleStoreWriteBase):
             new_module_data = {}
             for block_id in base_block_ids:
                 new_module_data = self.descendants(
-                    system.course_entry.structure['blocks'],
+                    copy.deepcopy(system.course_entry.structure['blocks']),  # copy or our changes like setting 'definition_loaded' will affect the active bulk operation data
                     block_id,
                     depth,
                     new_module_data