Add gdk_drag_find_window_for_screen(), so that we can interpret x_root /

Add gdk_drag_find_window_for_screen(), so that we can interpret x_root /

Mon Oct  7 15:48:44 2002  Owen Taylor  <otaylor@redhat.com>

        * gdk/gdkdnd.[ch] gdk/x11/gdkdnd-x11.c: Add
        gdk_drag_find_window_for_screen(), so that we can
        interpret x_root / y_root relative to the correct screen.

        * gdk/gdkdnd.c Makefile.am gdk/x11/gdkdnd-x11.c
        gdk/fb/gdkdnd-fb.c gdk/win32/gdkdnd-win32.c: New file.
        Move gdk_drag_find_window(), gdk_drag_get_protocol() here.

        * gtk/gtkdnd.c: Handle drags between screens; use
        a fallback icon for icons set as windows/pixmaps,
        move the drag icon between displays for icons set as
        pixbufs.

        * gdk/x11/gdkkeys-x11.c (update_keymaps): Fix infinite
        loop from last change.