Revert "server runs in single thread, added aditional message types, which are not used yet"

This reverts commit 014be61425aee7a58273d69745f8ed8963159507.
Merge branch 'feature/tcpip' of github.com:roboterclubaachen/xpcc into feature/tcpip
added network communication example and fixed one deadlock, which could appear during connection. There seems to be another datarace.