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.

examples/simple_ssl/simple.ini

@@ -0,0 +1,28 @@
+##########################################################
+### EiffelWeb settings for related connector           ###
+### Mostly for EiffelWeb standalone connector          ###
+### See {WGI_STANDALONE_CONSTANTS} for default values. ###
+##########################################################
+
+### Connection settings
+port=9090
+#max_concurrent_connections=100
+#max_tcp_clients=100
+
+### Timeout settings
+#socket_timeout=60
+#socket_recv_timeout=5
+
+### Persistent connection settings
+#keep_alive_timeout=15
+#max_keep_alive_requests=100
+
+### SSL settings
+# enable SSL, with file certificate.
+ssl_enabled=true
+ssl_ca_key=simple.key
+ssl_ca_crt=simple.crt
+
+### App settings
+verbose=true
+verbose_level=ALERT