Don't log an incomprehensible error when the watched directory itself is deleted, but generate wxFSW_EVENT_DELETE for it. This is consistent with the behaviour under Unix and generally more useful. Closes #13294. git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@76186 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775