[Echo.API.*] get rid of "requestType" parameter by updating live updates machinery; cleanup code base
[Echo.API.Transports.WebSocket] add interface function to determine connection status;
[Echo.API.Request] update docs + updating transport config in case of sending request;
[Echo.StreamServer.API.*] updating live updates config with transport handlers; "recurring" parameter backwards compatibility; establish connection over WS only once;
[Echo.StreamServer.Controls] update docs