New tracking_code setting that inserts HTML code in the footer of every page

app/inc/config.template.php

@@ -85,6 +85,7 @@ const TIME_EDIT_LINK_EMAIL = 60;
 $config = [
     /* general config */
     'use_smtp' => true,                     // use email for polls creation/modification/responses notification
+    'tracking_code' => '',                  // add HTML code to every page, useful for tools like Piwik
     /* home */
     'show_what_is_that' => true,            // display "how to use" section
     'show_the_software' => true,            // display technical information about the software

app/inc/smarty.php

@@ -33,6 +33,9 @@ $smarty->assign('use_nav_js', strstr($_SERVER['SERVER_NAME'], 'framadate.org'));
 $smarty->assign('locale', $locale);
 $smarty->assign('langs', $ALLOWED_LANGUAGES);
 $smarty->assign('date_format', $date_format);
+if (isset($config['tracking_code'])) {
+    $smarty->assign('tracking_code', $config['tracking_code']);
+}
 
 // Dev Mode
 if (isset($_SERVER['FRAMADATE_DEVMODE']) && $_SERVER['FRAMADATE_DEVMODE']) {

tpl/page.tpl

@@ -37,5 +37,8 @@
 
 </main>
 </div> <!-- .container -->
+{if isset($tracking_code)}
+    {$tracking_code}
+{/if}
 </body>
 </html>