Updated localization file for de-DE

git-svn-id: https://plugins.svn.wordpress.org/wp-ajaxify-comments/trunk@833261 b8457f37-d9ea-0310-8a92-e5e31aec5664
Set stable tag to 0.20.0

git-svn-id: https://plugins.svn.wordpress.org/wp-ajaxify-comments/trunk@833263 b8457f37-d9ea-0310-8a92-e5e31aec5664