commit version 1.3.1 with internationalization

git-svn-id: https://plugins.svn.wordpress.org/digitalkomix/trunk@1038140 b8457f37-d9ea-0310-8a92-e5e31aec5664
forgot to upgrade version in digitalkomix.php!

git-svn-id: https://plugins.svn.wordpress.org/digitalkomix/trunk@1038146 b8457f37-d9ea-0310-8a92-e5e31aec5664