bug#14471: 24.1.50; GTK3 shows resize handle which cannot be disabled

[martin rudalics <rudalics@gmx.at>]

 > Does that mean that this is an issue with the window manager and not with Emacs?

I'm not sure whether we should call it an issue.  There's a number of
issues involved though:

- If I'm not mistaken, GTK allows to regulate the appearance of the
   grip on all windows with the help of ressource settings.  So the
   order seems to be (1) those settings, (2) the application's wish,
   (3) the window manager's wish, (4) GTK's default value.  Peter
   should probably use (1) to fix this issue on his system.

- Ideally, a resize grip is shown iff (i) the associated window can be
   resized and (ii) switching between states where (i) changes is
   sufficiently infrequent (to avoid too much noise during redrawing).
   Since (i) can be hard, showing a grip even when the window cannot be
   resized does not necessarily qualify as a bug.

- Using a tiling window manager does not inherently preclude resizing
   windows in two directions simultaneously.  I'm not aware of one that
   offers such a feature but it would be fairly easy to provide one for
   Emacs' windows (I mean windows, not frames).

Finally, note that GTK has deprecated resize grips since version 3.14.

martin