Implement token refresh mechanism

Change-Id: Id58e14f663ebdd86f3f2206d4bfb9ad5d87a35fa
diff --git a/lib/Kalamar.pm b/lib/Kalamar.pm
index a72ead5..54fbe09 100644
--- a/lib/Kalamar.pm
+++ b/lib/Kalamar.pm
@@ -185,7 +185,9 @@
     $self->plugin('MailException' => $self->config('MailException'));
   };
 
-  # Load further plugins
+  # Load further plugins,
+  # that can override core functions,
+  # therefore order may be of importance
   if (exists $conf->{'plugins'}) {
     foreach (@{$conf->{'plugins'}}) {
       $self->plugin('Kalamar::Plugin::' . $_);