added dropdown selection for product code

git-svn-id: https://plugins.svn.wordpress.org/ip2location-country-blocker/trunk@863922 b8457f37-d9ea-0310-8a92-e5e31aec5664
allow user to custom their own error page.

git-svn-id: https://plugins.svn.wordpress.org/ip2location-country-blocker/trunk@868410 b8457f37-d9ea-0310-8a92-e5e31aec5664