wibble: Import raii (defer) patch from upstream.
concurrentqueue: Fix potential problem in signalling and add timed
dequeue.
driver: Some refactoring.
heartbeat: Add heartbeat manager.
serialization: Add type ElevatorCommand.
command: Serialieable type for sending commands to elevator.
restartwrapper: Wrapper which allows to automatically restart function
if it throws specified exception.

Mostly to be used when starting threads:
std::thread( restartWrapper( foo ), bar, baz )

Default behavior is to catch GenerallAssertionFailure (and let other
exceptions go up).