Change all time conversions. Yech. New timer units in microseconds breaks...

Change all time conversions.  Yech.  New timer units in microseconds breaks all existing logic that used milliseconds in the conversions.  Something likely got broken doing this, probably because I confused a MSEC2TICK conversion with a TICK2MSEC conversion.  Also, the tickless OS no appears fully functional and passes the OS test on the simulator with no errors