Time Duration Show/Hide Feature Added

git-svn-id: https://plugins.svn.wordpress.org/easy-pricing-table-manager/trunk@973254 b8457f37-d9ea-0310-8a92-e5e31aec5664
new feature added

git-svn-id: https://plugins.svn.wordpress.org/easy-pricing-table-manager/trunk@973257 b8457f37-d9ea-0310-8a92-e5e31aec5664