Add contributor stranger-jp

git-svn-id: https://plugins.svn.wordpress.org/page-navi-slider/trunk@775518 b8457f37-d9ea-0310-8a92-e5e31aec5664
Add contributor stranger-jp

git-svn-id: https://plugins.svn.wordpress.org/page-navi-slider/trunk@775519 b8457f37-d9ea-0310-8a92-e5e31aec5664