boards: initial import of iot-lab_M3

boards/iot-lab_M3/Makefile.dep

boards/iot-lab_M3/Makefile.include

boards/iot-lab_M3/board.c

boards/iot-lab_M3/board_init.c

boards/iot-lab_M3/dist/debug.sh

boards/iot-lab_M3/dist/flash.sh

boards/iot-lab_M3/dist/reset.sh

boards/iot-lab_M3/drivers/Makefile

boards/iot-lab_M3/drivers/at86rf231_driver.c

boards/iot-lab_M3/drivers/at86rf231_spi1.c

boards/iot-lab_M3/drivers/iot-lab_M3-uart.c

boards/iot-lab_M3/include/at86rf231_spi1.h

boards/iot-lab_M3/include/board.h

boards/iot-lab_M3/include/periph_conf.h

boards/iot-lab_M3/system_stm32f1.c

cpu/cortex-m3_common/include/cmsis_system.h

cpu/cortex-m3_common/thread_arch.c

cpu/cortexm_common/crash.c

cpu/stm32f1/cpu.c

cpu/stm32f1/hwtimer_arch.c