wxFileDialog::GetPath() didn't return the value set by a previous call to SetPath() in wxMSW version. Fix this and also implement SetPath() and SetDirectory() methods in the generic versions in the same way as SetFilename(). Closes #3672. git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@62722 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775