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.
Add the classes Task, TaskBase and TaskQueue. TaskQueue queue is an
interface class which can be implemented by anything which can run
code. Task and TaskBase are concrete classes which allow callbacks
to be posted to a TaskQueue to be run.
Add the ByteBuffer class which is similar to the CircularBuffer class
but uses dynamic memory rather than template parameters and is
optimized for byte transfers. This is required for USBAudio which
needs a high performance circular buffer which can be resized at
runtime.
Add the OperationList class to simplify managing async operations.
Add a callback to the AsyncOp class so completion can be signaled with
another mechanism. Finally rework the lock handling so AsyncOp::wait
is passed the lock to use rather than taking it in a constructor.
Add an allocation free linked list implementation. Additionally add
the class AsyncOp which provides blocking and wakeup funcionality
to simplify making asynchronous operations block.