LDEV-4935 Secure lesson chat (presence) websocketsNickname is taken from session, not from incoming parameters. User getschecked if he participates in the given lesson.Simplified code, clean up.
LDEV-3653 Add websocket server and client code. Add Ant code for deploying the server class to <WAR>/WEB-INF/classes folder for WildFly to pick it up on start up. Rearange, clean up and formatting.