Remaining ideas
===============

* Revisit efficiency of the relay and handshake code only with measurements;
  correctness and descriptor ownership take priority.
* Consider optional support for WinGate and other non-standard proxies.
* Consider optional TLS-to-proxy, NTLM/Digest, PAC, or config-file support
  only if a concrete interoperability requirement justifies the added
  dependencies and attack surface.
* Historical SunOS 4.1.3 portability work is not maintained.
