Plugin API: add 'check_recent' hook with possibility to control folders list used on check-recent action

program/steps/mail/check_recent.inc

@@ -34,9 +34,14 @@ if ($check_all) {
 }
 else {
     $a_mailboxes = (array) $current;
-    if ($a_mailboxes[0] != 'INBOX')
+    if ($current != 'INBOX') {
         $a_mailboxes[] = 'INBOX';
     }
+}
+
+// Control folders list from a plugin
+$plugin      = $RCMAIL->plugins->exec_hook('check_recent', array('folders' => $a_mailboxes, 'all' => $check_all));
+$a_mailboxes = $plugin['folders'];
 
 // check recent/unseen counts
 foreach ($a_mailboxes as $mbox_name) {