Define wxSetDetectableAutoRepeat() for X11-based ports only.

This function is not needed in wxGTK2 as GTK+ sets detectable auto-repeat on
its own in gdk_display_open() anyhow, so move its implementation to
src/x11/utilsx.cpp where it can be used by wxX11 and wxMotif which do need it.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@62001 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/gtk/app.cpp

@@ -438,8 +438,6 @@ bool wxApp::Initialize(int& argc_, wxChar **argv_)
     // we can not enter threads before gtk_init is done
     gdk_threads_enter();
 
-    wxSetDetectableAutoRepeat( true );
-
 #if wxUSE_INTL
     wxFont::SetDefaultEncoding(wxLocale::GetSystemEncoding());
 #endif