web-interface using scala-js and web sockets
added SocketConnections for the frontend;
new module: web-backend, based on spray-can and spray-websocket;
a basic websocket push-server added.
frontend: added GenTemplate and denTemplates task for sbt;
frontend: ChessBoard;
common: messages to send between fe/be;
backend: messages serialization to Json;
frontend: basic messages reading;
frontend: added queen-info;
Merged web: fronted - scala-js; backend: spray-websocket; common - messages;
fronted: ChessBoard and QueenInfo;