Modifications
- load_html_string is deprecated since webkitgtk 1.1.1
- set_from_stock_name is deprecated since gtk 3.10
- using 'encoding=utf8' prevents an exception to rise when calling thus
  using env vars in the command line (like sudo -E LANG=fr python thus.py)
- update DBusException in misc
- sort to_be_deleted and changelist in installation_advanced