Fixed seldom blank desktop with no visible icons

 o the screen saver code was not protected against multithreading.
    occasionally blocking the X event flow, which might explain VBox and RPi sudden blank screens.
 o moved the screen saver thread creation after the desktop icons are drawn on the desktop
 o increased inactivity timeout check to every 1 minute.
Updated kdeskrc and icon files to fix font position
Merge pull request #31 from KanoComputing/boot-empty

Fixed seldom blank desktop with no visible icons