+/**
+ * @brief Transform a remote URL into a local one
+ *
+ * This function only performs the URL replacement on http URL and if the
+ * provided URL isn't local, "the isn't deactivated" (sic) and if the config
+ * system.proxy_disabled is set to false.
+ *
+ * @param string $url The URL to proxyfy
+ * @param bool $writemode Returns a local path the remote URL should be saved to
+ * @param string $size One of the PROXY_SIZE_* constants
+ *
+ * @return string The proxyfied URL or relative path
+ */
+function proxy_url($url, $writemode = false, $size = '') {