Add a client default configuration file

[sthibaul]

Is your feature request related to a problem? Please describe.
When setting up server on e.g. a TCP/IP port, one has to tell each and every client of the change

Describe the solution you'd like
We could configure that in a client-side configuration file, e.g. /etc/speech-dispatcher/client-default.conf

Thanks Sebastian Humenda for that report