Replace the AsyncDone event with an explicit done callback in the node
to signal completion of an async operation.
Pass read and write fd together with the transport
Make a default logger and mapper in a .h file to be used by examples
Remove logger and mapper from libs
Make method to set the default mapper for the debug methods
Improve event and command init so that it can be used more easily
as compound literals.
Improve volume
Make it possible to use graph scheduler in test-mixer
