improve logging

[sevenautumns]

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.