WiFi Walkie Talkie

This program transmits sound recorded from microphone to some other devices
running the same program on the same network segment, so works like Walkie
Talkie radio.

Devices find each other by Android NSD (aka Bonjour), no any configuration
required. Unfortunately Android NSD implementation is not stable enough, so
sometimes application can not establish connection properly. Application restart
or device reboot usually helps. Audio data is being transmitted by the unicast
channel, so each device works as a server and as a client at the same time.

Program was implemented as a demonstration of JS-Collider: Java high performance
scalable NIO framework, see https://github.com/js-labs/js-collider.