Release Note: Allow use of SIO_LOOPBACK_FAST_PATH on Microsoft Windows

Applications running on server editions of Microsoft Windows that make heavy use of loopback connections may see latency and performance improvements if SIO_LOOPBACK_FAST_PATH is enabled. The system property "jdk.net.useFastTcpLoopback" controls whether the JDK enables SIO_LOOPBACK_FAST_PATH on Microsoft Windows. It is disabled by default but can be enabled by setting the system property on the command line with `-Djdk.net.useFastTcpLoopback` or `-Djdk.net.useFastTcpLoopback=true`.