Refactoring HAL
- This should finally fix issues with timers/systick
-- Expire values were calculated incorrectly for timers
- Unix/Linux style load calculation
-Fixed load calculation
-Fixed thread penalties
-Added more demo code for testing purposes
-Removed old code from sched.c

Signed-off-by: Olli Vanhoja <olli.vanhoja@ninjaware.fi>