Added cachebuster

Resolves #802.

docs/faq.rst

@@ -66,6 +66,13 @@ Archiving means that per day only one record is stored with averages. This still
 
 The retention period tells the monitor how long to keep records in the archive table.
 
+How to disable caching?
+------------------------
+
+Caching can be stopt by using a unique url. Place `%cachebuster%` in the url,
+this will be replaced with the value of time().
+Example: https://example.com?%cachebuster% will run as https://example.com?571768757.
+
 Configuration
 +++++++++++++
 

src/includes/functions.inc.php

@@ -382,6 +382,8 @@ function psm_curl_get($href, $header = false, $body = true, $timeout = null, $ad
 		curl_setopt($ch, CURLOPT_USERPWD, $website_username.":".$website_password);
 	}
 
+	$href = preg_replace('/(.*)(%cachebuster%)/', '$0'.time(), $href);
+
 	curl_setopt($ch, CURLOPT_URL, $href);
 
 	$proxy_url = psm_get_conf('proxy_url', '');