prevent NPE
* shutdown console if a shell-session is shutdown (release resources)
* implements remote-completer response
* outsource the dispatching of incoming messages to it own class
* add some javadoc and log
use the next version of JSS cause in this version the error-output will
be flushed
* extend ReadLine message for transfer the mask-character too
* refactor the wait mechanism for readline and output
There is now a handshake-phase after a beginning connection. In this
phase the client (and server) can request some information (such like
the history content). After that phase the shell will be start the
command-loop.