Rewrite the document indexer to allow single index rebuilds,

less locks and improve performance.

Signed-off-by: Roberto Rosario <roberto.rosario.gonzalez@gmail.com>

mayan/apps/document_indexing/api_views.py

@@ -175,4 +175,4 @@ class APIDocumentIndexListView(generics.ListAPIView):
             obj=document
         )
 
-        return document.node_instances.all()
+        return document.index_instance_nodes.all()