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.e

@@ -0,0 +1,100 @@
+note
+	description: "[
+		API to perform actions like opening and closing the connection, sending and receiving messages, and listening
+		for events triggered by the server
+	]"
+	author: ""
+	date: "$Date$"
+	revision: "$Revision$"
+
+deferred class
+	WEB_SOCKET
+
+inherit
+
+	WEB_SOCKET_CONSTANTS
+
+feature -- Access
+
+	uri: READABLE_STRING_GENERAL
+			-- WebSocket Protocol defines two URI schemes, ws and wss for
+			-- unencrypted and encrypted traffic between the client and the server.
+
+	port: INTEGER
+			-- Current WebSocket protocol.
+
+	ws_port_default: INTEGER = 80
+			-- WebSocket Protocol uses port 80 for regular WebSocket connections.
+
+	wss_port_default: INTEGER = 443
+			--  WebSocket connections tunneled over Transport Layer Security (TLS) use port 443.
+
+	protocols: detachable LIST [STRING]
+			-- List of protocol names that the client supports.
+
+	protocol: STRING
+			-- Client-Server protocol selected.
+			-- Has the result fo protocol negotiation between client and the server
+			-- By default it's an empty string.
+
+	is_tunneled: BOOLEAN
+			-- Is the current connection tunneled over TLS/SSL?
+		local
+			l_uri: STRING
+		do
+			l_uri := uri.as_lower.as_string_8
+			Result := l_uri.starts_with ("wss") -- TODO extract to ws_constants.
+		end
+
+	ready_state: WEB_SOCKET_READY_STATE
+			-- Connection state
+
+feature -- Methods
+
+	send (a_message: STRING)
+			-- Send a message `a_message'
+		require
+			is_open: ready_state.is_open
+		deferred
+		end
+
+	close (a_id: INTEGER)
+			-- Close a websocket connection with a close id : `a_id'
+		deferred
+		ensure
+			is_closed: ready_state.is_closed
+		end
+
+	close_with_description (a_id: INTEGER; a_description: READABLE_STRING_GENERAL)
+			-- Close a websocket connection with a close id : `a_id' and a description `a_description'
+		deferred
+		ensure
+			is_closed: ready_state.is_closed
+		end
+
+feature -- Change Element
+
+	set_protocol (a_protocol: STRING)
+			-- Set `protocol' with `a_protocol'
+		do
+			protocol := a_protocol
+		ensure
+			protocol_set: protocol = a_protocol
+		end
+
+	set_protocols (a_protocols: detachable ITERABLE [STRING])
+		local
+			l_protocols: LIST [STRING]
+		do
+			if a_protocols /= Void then
+				create {ARRAYED_LIST [STRING]} l_protocols.make (0)
+				across
+					a_protocols as ic
+				loop
+					l_protocols.force (ic.item)
+				end
+				protocols := l_protocols
+			end
+		end
+
+end