making line numbers work

git-svn-id: https://plugins.svn.wordpress.org/codepen-embedded-pen-shortcode/trunk@991527 b8457f37-d9ea-0310-8a92-e5e31aec5664
upping version, tested up to 4.0

git-svn-id: https://plugins.svn.wordpress.org/codepen-embedded-pen-shortcode/trunk@991528 b8457f37-d9ea-0310-8a92-e5e31aec5664