Wayland: use CROSSHAIR not MOUSE cursor.

Attempting to use Gdk.CursorType.MOUSE raises an exception on Wayland,
and it's horribly ugly with X11 scaled cursors.

Catch and log any exceptions when this happens, for some robustness.

Update copyright statement.

Fixes #809.

gui/buttonmap.py

@@ -1,5 +1,5 @@
 # This file is part of MyPaint.
-# Copyright (C) 2012 by Andrew Chadwick <a.t.chadwick@gmail.com>
+# Copyright (C) 2012-2017 by Andrew Chadwick <a.t.chadwick@gmail.com>
 #
 # This program is free software; you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
@@ -12,6 +12,7 @@
 from __future__ import division, print_function
 
 from gettext import gettext as _
+import logging
 
 from gi.repository import Gtk
 from gi.repository import Gdk
@@ -21,6 +22,8 @@
 import lib.xml
 import widgets
 
+logger = logging.getLogger(__name__)
+
 
 def button_press_name(button, mods):
     """Converts button number & modifier mask to a prefs-storable string.
@@ -540,9 +543,12 @@ def _bp_edit_dialog_set_standard_hint(self, dialog):
 
     def _bp_edit_box_enter_cb(self, evbox, event):
         window = evbox.get_window()
-        cursor = Gdk.Cursor.new_for_display(
-            window.get_display(), Gdk.CursorType.MOUSE)
-        window.set_cursor(cursor)
+        disp = window.get_display()
+        try:  # Wayland themes are a bit incomplete
+            cursor = Gdk.Cursor.new_for_display(disp, Gdk.CursorType.CROSSHAIR)
+            window.set_cursor(cursor)
+        except:
+            logger.exception("Cursor setting failed")  # and otherwise ignore
 
     def _bp_edit_dialog_response_cb(self, dialog, response_id, editable):
         if response_id == Gtk.ResponseType.OK: