[RELEASE] 13.0.4 -- Bugfix release

Some small bugfixes and enhancements.

See release page on github for details:
https://github.com/in2code-de/powermail/releases/

Author: mschwemer

ext_emconf.php

@@ -6,7 +6,7 @@
         and easy to use mailform extension with a lots of features
         (spam prevention, marketing information, optin, ajax submit, diagram analysis, etc...)',
     'category' => 'plugin',
-    'version' => '13.0.3',
+    'version' => '13.0.4',
     'state' => 'stable',
     'author' => 'Powermail Development Team',
     'author_email' => 'service@in2code.de',