Fixed SSL support on the httpd component, and also on the EiffelWeb standalone connector.

- the standalone connector support for SSL, is using certicate files for now (no in-memory support).
  - to enable ssl support, set ecf variable `httpd_ssl_enabled=true`.
  - added the `simple_ssl` example to demonstrate how to have standalone ssl server.
    (be careful when using EiffelNet SSL and the http_client library, disable the libcurl
      via ecf variable `libcurl_http_client_disabled=true` )

Added support for recv timeout to the EiffelWeb standalone connector.
  - made EiffelWeb compilable with 16.05 and upcoming 16.11.
    Done via ecfs condition on version to accept EiffelNet with recv_timeout (from 16.11), and without (until 16.05).
  - adding recv timeout prevents server to hang for ever if a client wait too long to send data.

Updated various comments.

library/server/ewsgi/connectors/standalone/lib/httpd/ssl/httpd_socket_factory.e

@@ -0,0 +1,20 @@
+note
+	description: "Summary description for {HTTPD_SOCKET_FACTORY}."
+	date: "$Date$"
+	revision: "$Revision$"
+
+deferred class
+	HTTPD_SOCKET_FACTORY
+
+feature -- Access
+
+	new_client_socket (a_is_secure: BOOLEAN): HTTPD_STREAM_SOCKET
+		do
+			if a_is_secure then
+				create {HTTPD_STREAM_SSL_SOCKET} Result.make_empty
+			else
+				create Result.make_empty
+			end
+		end
+
+end