style of buy-image-credit

git-svn-id: https://plugins.svn.wordpress.org/wp-fastest-cache/trunk@1036023 b8457f37-d9ea-0310-8a92-e5e31aec5664
click event of buy image credit

git-svn-id: https://plugins.svn.wordpress.org/wp-fastest-cache/trunk@1036024 b8457f37-d9ea-0310-8a92-e5e31aec5664