os: split timed_semaphore and timed_thread

Issue #1211
fixup: reformat timeout_thread according to nfeske

Issue #1211
fixup: reformat timed_semaphore according to nfeske

Issue #1211
nova: replace timed_semaphore with nova specific

Issue #1211
fixup: reformat timed_semaphore according to nfeske

Issue #1211
nova: use kernel sm_ctrl for usleep/msleep

Issue #1211