- Reverse connections must be maintained to ensure messages are
processed in order. (Whoops!)
- The clipboard context must remain live in order for the data to
remain available for applications, at least on X11. (And it couldn't
hurt elsewhere, either, I guess.)
- Print out the server version at startup time, so we can be sure what
we're talking to.
- Print out the full details of the error when something goes wrong
with `browse` or `clip`.
This allows forwarding ports that you would otherwise not be able to
see. More dangerous, probably not what you want most of the time, but
OK for now.
(I continue to resist adding clap as a dependency.)
