It is not used anymore.

This reverts commit 1ad36d72.
It causes issues with tray icons.

- Drop altlinux-menus requires.
- Rename and fix fusion-icon.desktop for autostart.
- backgrounds: Replace slinux_spring_*.png with slinux_spring_*.jpg.

- indexhtml: change link to user manual (by Artem Zolochevskiy).
- menu: Drop unneeded desktop files.
- etcscel: Changed display type of xkb plugin.

Drop driconf.desktop, eiskaltdc.desktop,
sonata.desktop, Kino.desktop, audacity.desktop.