Revert "Simplify listen port setup"
Revert "Simplify listen port setup"

This reverts commit 0cf4c7838793ef1b8a6d203c12308c54453cc8c8.

Also improve tcp/unix choice when PORT env variable is set

cloudfoundry/garden-windows,cloudfoundry-incubator/garden-windows,stefanschneider/garden-windows,cloudfoundry-incubator/garden-windows,cloudfoundry/garden-windows,cloudfoundry-incubator/garden-windows,cloudfoundry/garden-windows,stefanschneider/garden-windows,stefanschneider/garden-windows