German translation

Translated new phrases in configcheck.inc.php and setting.inc.php to German.

The sentence "MODX recommends this setting be disabled unless you need to explicitly allow users to submit MODX tags, numeric entities, or HTML script tags via the POST method to a form in your site" ($_lang['configcheck_allowtagsinpost_context_enabled_msg'] and $_lang['configcheck_allowtagsinpost_system_enabled_msg']) is a little bit unclear in my eyes. First, I guess "numeric HTML entities" (maybe with an example) would be easier to understand. And then I don't understand how a POST request could possibly be sent TO a form - it's sent FROM a form to a script that hopefully evaluates the transmitted data... Maybe this could be changed some time.

Signed-off-by: Jan-Christoph Ihrens <ihrens@cc-services.de>