System test no longer exits on grey button

Changed system test to no longer exit on grey button. Instead, one of
the cycling modes will prompt the user to exit the program by pressing
either arrow keys. Pressing the grey button will cycle backwards one
function, so that accidentally skipping over the desired function will
not end in having to cycle through again. I also changed the
nxtExitTicks to one million, so that one cannot accidentally exit the
program. Also added more EndTimeSlice() calls