[PATCH 4 of 7] parsers: handle refcounting of "parents" consistently

[Yuya Nishihara]

On Mon, 13 Mar 2017 22:15:46 -0700, Gregory Szorc wrote:
> # HG changeset patch
> # User Gregory Szorc <gregory.szorc at gmail.com>
> # Date 1489452553 25200
> #      Mon Mar 13 17:49:13 2017 -0700
> # Node ID d600bd4edd62b3ee74730f1282e53b9d596bbaec
> # Parent  6d3b13f243bea2c9200eecb827d7ec0ea771fc54
> parsers: handle refcounting of "parents" consistently
> 
> Py_None can be refcounted like any other Python object. So
> do that.

Sure, queued this, thanks.