improve logging

Right now, logging is not performant and can fill up the complete `UnixDatagram` of a partition, resulting in messages and other requests being silently dropped. The problem of a filled up `UnixDatagram` can be solved with the new syscall system. The performance problem could be solved by preparing a `Stdio` for stdout and stderr (`application_message` and `application_error`) and handing them to the `Command` struct of each partition. This `Stdio` could be made from a pipe.