compile fixes for EMX

minor doc updates
  minor fixes for problems with rdrag and ldrag in tree ctrl and list ctrl


git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@3392 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/gtk/app.cpp

@@ -669,7 +669,11 @@ int wxEntry( int argc, char *argv[] )
 {
     gtk_set_locale();
 
+#if wxUSE_WCHAR_T
     if (!wxOKlibc()) wxConvCurrent = &wxConvLocal;
+#else
+    if (!wxOKlibc()) wxConvCurrent = (wxMBConv*) NULL;
+#endif
 
     gtk_init( &argc, &argv );