Deprecate wait() in favour of acquire(), try_acquire(),
try_acquire_for() and try_acquire_until().
Brings Semaphore more into line with CMSIS-RTOS 2 (which uses "acquire"),
itself (as it has "release"), and other classes having "try", "try for"
and "try until".
Also steps away from vague "wait" term - the primary operation here is
to acquire the semaphore, and this will of course sleep.