Merge pull request #1456 from haukepetersen/board_stm32f3discovery

boards/stm32f3discovery/Makefile

boards/stm32f3discovery/Makefile.include

boards/stm32f3discovery/board.c

boards/stm32f3discovery/dist/debug.sh

boards/stm32f3discovery/dist/gdb.conf

boards/stm32f3discovery/include/board.h

boards/stm32f3discovery/include/periph_conf.h

cpu/cortex-m4_common/thread_arch.c

cpu/stm32f3/Makefile

cpu/stm32f3/Makefile.include

cpu/stm32f3/cpu.c

cpu/stm32f3/hwtimer_arch.c

cpu/stm32f3/include/cpu-conf.h

cpu/stm32f3/include/hwtimer_cpu.h

cpu/stm32f3/include/stm32f303xc.h

cpu/stm32f3/io_arch.c

cpu/stm32f3/lpm_arch.c

cpu/stm32f3/periph/Makefile

cpu/stm32f3/periph/gpio.c

cpu/stm32f3/periph/timer.c