Update readme.txt with release info

git-svn-id: https://plugins.svn.wordpress.org/jc-importer/trunk@1025313 b8457f37-d9ea-0310-8a92-e5e31aec5664
Add author/plugin urls

git-svn-id: https://plugins.svn.wordpress.org/jc-importer/trunk@1025314 b8457f37-d9ea-0310-8a92-e5e31aec5664