Correctly escape the path when writing the autostart .desktop file

[denilsonsa]

The Exec key from ~/.config/autostart/arandr-indicator.desktop file is written without any escaping. This may lead to an invalid autostart entry that will fail to launch the tool, if the path contains spaces or other characters that require escaping.

Sample path: /home/username/Área de Trabalho/arandr-indicator.py Related bug on PyXDG: https://bugs.freedesktop.org/show_bug.cgi?id=83034 Documentation: http://standards.freedesktop.org/desktop-entry-spec/latest/ar01s06.html