Added option to enable/disable range and change start and end columns to BIGINT

git-svn-id: https://plugins.svn.wordpress.org/ip-based-login/trunk@858786 b8457f37-d9ea-0310-8a92-e5e31aec5664
Added dropdown for users list and fixed a typo

git-svn-id: https://plugins.svn.wordpress.org/ip-based-login/trunk@859532 b8457f37-d9ea-0310-8a92-e5e31aec5664