Merge pull request #822 from LudwigOrtmann/reboot_signature

core/include/kernel.h

core/include/kernel_internal.h

core/reboot.c

cpu/arm_common/arm_cpu.c

cpu/arm_common/crash.c

cpu/lpc1768/cpu.c

cpu/lpc1768/crash.c

cpu/msp430-common/cpu.c

cpu/msp430-common/crash.c

cpu/native/crash.c

cpu/native/native_cpu.c

sys/shell/commands/sc_sys.c