Merge pull request #1502 from Kijewski/issue-1485

tests/hwtimer_wait/Makefile

tests/hwtimer_wait/main.c

tests/ipc_pingpong/Makefile

tests/ipc_pingpong/main.c

tests/ipc_pingpong/tests/01-test

tests/irq/Makefile

tests/irq/main.c

tests/mutex_unlock_and_sleep/Makefile

tests/mutex_unlock_and_sleep/main.c

tests/nativenet/Makefile

tests/nativenet/main.c

tests/net_if/Makefile

tests/net_if/main.c

tests/pipe/Makefile

tests/pipe/main.c

tests/pnet/Makefile

tests/pnet/main.c

tests/posix_semaphore/Makefile

tests/posix_semaphore/main.c

tests/posix_sleep/Makefile