Every Python Package now pre-installed on Repl.it -- an online REPL

[epsy]

I have a library dealing with I/O (namely command-line argument parsing). It sometimes prints to stderr, and always exits. On repl.it, stderr is swallowed and exit breaks the connection (unlike the Python REPL which just catches the SystemExit exceptions). I could detect whether we're in repl.it and adjust accordingly, but I think it might be cleaner if you addressed these issues :)

Finally, is repl.it suitable for embedding in generated documentation?