MSHTML NVDAObject: reorder __init__ a bit so as to make sure that HTMLNode property already exists before super is called. Fixes an error in Windows Live Mail where code in the appModule was asking for the role in event_NVDAObject_init (before HTMLNode property existed). Also fix findBestClass so that it only ads MSHTML to the class list if it isn't already there. (Its possible that IAccessible already ads it when calling super).