Feature request: silent mode

[berlic]

Hello.

Thanks for your work!

Could you please implement some option to prevent messages to process' stdout?

I use epdb as remote debugger with epdb.serve(). When telnet server is started, it spits out Serving on port... to debugged process' stdout (here). But my process must produce valid JSON as its output.

I commented out this line to prevent printing, but may be there is better way to control epdb's silent mode.

[wfscheper]

@berlic, does PR #10 address your use case?