NVIC priority change
Use 'better' macros to handle priority. This simplifies passing priority to function and new ATOMIC_BLOCK macro
Merge pull request #156 from ledvinap/feature-nvic

NVIC priority change
Merge remote-tracking branch 'refs/remotes/upstream/master' into local

Conflicts:
	src/main/drivers/nvic.h
	src/main/drivers/timer.c