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.
Matches rest of RTOS class timeout parameters by using the unit name. Remove ambigious statement in reference to 0 ms being no-timeout as a timeout of 0 causes the function to not block and return immediately (osWaitForever is used as no timeout as it will wait forever)
Given the 64-bit timebase, add wait_until to Semaphore.
Naming is based on Thread::wait_until.
pthreads uses "timedwait", but that's not a good fit against our
existing wait() - pthreads only has an absolute-time wait, not relative.
Various RTOS classes were storing their CMSIS-RTOS creation attribute
structure as a member, when it's not required after construction. Reduce
memory by eliminating this member.