Merge remote-tracking branch 'cloudant/couchdb-3302'

Closes #89
diff --git a/src/fabric_rpc.erl b/src/fabric_rpc.erl
index 679a305..80b110a 100644
--- a/src/fabric_rpc.erl
+++ b/src/fabric_rpc.erl
@@ -422,6 +422,7 @@
         Parser ! {get_bytes, Ref, self()},
         receive
             {bytes, Ref, Bytes} ->
+                rexi:reply(attachment_chunk_received),
                 Bytes;
             {'DOWN', ParserRef, _, _, Reason} ->
                 throw({mp_parser_died, Reason})