Rename `waitAfterComplete` option

`waitAfterComplete` is renamed to `leaveRemoteOpen` and is now command
line-only.

References #144
Merge branch 'master' into geezer
Forcibly close open sockets when closing the proxy

When `close` is called on the proxy, any sockets remaining open are
forcibly closed, allowing the proxy server to close.
Merge branch 'master' into geezer