* Use strings.TrimSuffix in ListenAndServe for TLS
This replaces the if/else statements with something simpler.
Interestingly, the first pull request I submitted to this library was
to fix the tcp6-tls case way back in 4744e915eb.
* Add SO_REUSEPORT implementation
Fixes#654
* Rename Reuseport field to ReusePort
* Rename supportsReuseport to match ReusePort
* Rename listenUDP and listenTCP file to listen_*.go