cpu: moved reboot_arch for cortex cpus
cpu/cortex-mX_common: fixed reboot_arch return val
cpu/cortex-mX_common: added delay to reboot_arch
Initial import of the updated srf02 driver with general i2c interface
Merge pull request #1871 from PeterKietzmann/add_srf02_general_i2c_if

drivers/srf02: adapted ultrasonic ranger driver to general i2c interface
Merge pull request #2047 from haukepetersen/fix_cortex_reboot

cpu: fixed and moved reboot_arch for cortex cpus
tests: define random default GPIOs to pass Travis builds
Merge pull request #2064 from thomaseichinger/sensor-features

tests: define random default GPIOs to pass Travis builds
tests: fix tests/posix_semaphore
posix: Fix missing `restoreIRQ()` in `sem_post()`
Merge pull request #1966 from Kijewski/semaphore-fix-irq

posix: Fix missing `restoreIRQ()` in `sem_post()`