Reuse http_network library.

Reintroduced HTTPD_STREAM_SOCKET for backward compatibility, and ease of usage.
Added websocket libraries (client, and protocol).

library/network/websocket/client/src/web_socket_subscriber.e

@@ -0,0 +1,61 @@
+note
+	description: "Summary description for {WEB_SOCKET_SUBSCRIBER}."
+	author: ""
+	date: "$Date$"
+	revision: "$Revision$"
+
+deferred class
+	WEB_SOCKET_SUBSCRIBER
+
+
+feature -- Events
+
+	on_websocket_ping (a_message: detachable STRING)
+			-- Send a ping in response to a received ping.
+		do
+		end
+
+
+	on_websocket_pong (a_message: detachable STRING)
+			-- Default implementation do nothing.
+		do
+		end
+
+
+	on_websocket_text_message (a_message: detachable STRING)
+			-- Default implementation do nothing.
+		do
+		end
+
+	on_websocket_binary_message (a_message: detachable STRING)
+			-- Default implementation do nothing.
+		do
+		end
+
+
+	on_websocket_open (a_message: detachable STRING)
+		do
+		end
+
+
+	on_websocket_close (a_message: detachable STRING)
+		do
+		end
+
+	on_websocket_error (a_error: detachable STRING)
+		do
+		end
+
+feature -- Handshake
+
+	on_websocket_handshake (request: STRING)
+			-- Default do nothing
+		deferred
+		end
+
+feature -- TCP connection
+
+	connection: HTTP_STREAM_SOCKET
+		deferred
+		end
+end