IAccessible NVDAObject's parent property: fix a very bad bug on my part, where Audacity would not work at all with NVDA (NVDA would just freeze). This may also fix a few other random crashes. The bug was introduced in r1870 where if the window class started with 'Mozilla' the Gecko node_child_of navRelation was tried, before trying accParent. However, for some odd reason, I had left some oder test code directly below it, which tried node_child_of no matter or not it was a Mozilla window. Of course many native implementations of MSAA would not understand this value and just get confused.