Added config parameter to allow self-signed certificates for the HTTP client

doc/config.markdown

@@ -267,8 +267,8 @@ Session
 define('SESSION_DURATION', 0);
 ```
 
-HTTP client proxy
------------------
+HTTP Client
+-----------
 
 If external HTTP requests need to be sent through a proxy:
 
@@ -279,6 +279,13 @@ define('HTTP_PROXY_USERNAME', '');
 define('HTTP_PROXY_PASSWORD', '');
 ```
 
+To allow self-signed certificates:
+
+```php
+// Set to false to allow self-signed certificates
+define('HTTP_VERIFY_SSL_CERTIFICATE', true);
+```
+
 Various settings
 ----------------