Changes

The mapping from priority to time is the following: if <tt>0</tt> prio corresponds time slice <tt>t</tt>, than <tt>8</tt> prio corresponds to time slice <tt>2 * t</tt>. Default time slice value is <tt>HZ/2</tt>. The main criteria for fairness at the moment is that if you set I/O prio of VE 1 to <tt>p1</tt> and I/O prio of VE 2 to <tt>p2</tt>, and <tt>p1 > p2</tt> then VE 1 should readdo more I/write(*) more O than VE 2. (*) writes are not completely supported at the moment