* Some Makefile cleanup.
* Also some register map sanitation to make way for NVIC code.
* Added nvic/scb plumbing.
* Cleaned up volatile declarations to be more consistent where appropriate.
Merge branch 'master' of github.com:cpmm/embedded

Conflicts:
	stm32f303c-eval/inc/gpio.h
	stm32f303c-eval/inc/nvic.h
	stm32f303c-eval/inc/scb.h
	stm32f303c-eval/src/gpio.c
	stm32f303c-eval/src/nvic.c
	stm32f303c-eval/src/scb.c
* Merge.