add translatation and new features (archives and authors)

git-svn-id: https://plugins.svn.wordpress.org/wp-sitemap-page/trunk@856689 b8457f37-d9ea-0310-8a92-e5e31aec5664
add link for a translation author

git-svn-id: https://plugins.svn.wordpress.org/wp-sitemap-page/trunk@859581 b8457f37-d9ea-0310-8a92-e5e31aec5664
add translations (de_DE)

git-svn-id: https://plugins.svn.wordpress.org/wp-sitemap-page/trunk@859582 b8457f37-d9ea-0310-8a92-e5e31aec5664