Patch Set 3: Looks good to me, but someone else must approve; No score

I changed the test that they now use CPU time. Thanks for Robins comments/links on that. Now they are in a state that the test results are quite stable.
I also changed the tests in a way that they can live with not so accurate CPU time clocks. On my laptop the VM returned new CPU time values only 0,01 seconds which was to bad to measure fast diffs. Now diffs are repeated until we see the CPU time clock changed its value at least 10 times.