Question marks for query strings.

As noticed by Ximin.
https://trac.torproject.org/projects/tor/ticket/9349#comment:20
Just include outermost transports in facilitator responses.

This is in contradiction to what I proposed in
https://trac.torproject.org/projects/tor/ticket/9349#comment:20. Really
there's no need for the proxy to know that there's obfs2 underneath; it
just has to make a connection and copy bytes.
Polling requests include client port numbers.
Punctuation.
Straighten up handling of --relay-file.
Make it only a warning if no relays were configured.
Add default relay configuration.
Install and use default relays file.
Just let it crash if there's a problem loading the relays file.
Use setdefault.
Resolve outside of add_relay.
I think of these params as switched.
Do this computation in steps.
Collapse vertical space in comments.
Use "transports" for a transport chain tuple everywhere.
Whitespace.
Comments and variable names.
Use RELAYS in place of options.relays.

It's not really an option, just a global variable.
Store relays as addr tuples, not as strings.
Fix what the global RELAYS looks like.