Unify cursor name lookup handling on linux

commit bd3f219344eec2706f0b5f2636201f90951fdc33
Author: Philipp Brüschweiler <blei42@gmail.com>
Date: Tue Aug 21 20:36:16 2012 +0200

    toytoolkit: try multiple names when loading cursors
    
    The correspondence between cursor functions and names of cursors has
    never been standardized. As a consequence, each cursor function can be
    represented as a cursor with one of several names. Be more robust when
    loading cursor by trying all known names that correspond to a cursor.
    
    This should fix https://bugs.freedesktop.org/show_bug.cgi?id=50487
    and https://bugs.freedesktop.org/show_bug.cgi?id=52609 a bit more
    thoroughly.

 clients/window.c | 105 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++----------
 1 file changed, 95 insertions(+), 10 deletions(-)

commit 3aa4c8d635e25117075121bb40040f9be6ac2c44
Author: Martin Gräßlin <mgraesslin@kde.org>
Date:   Wed Mar 18 07:45:16 2015 +0100

    Add cursor resolving alternatives
    
    The alternative names are taken from the xcursortheme kcm in
    plasma-desktop. An example theme where they are needed is "dmz".