* Update to v2.1.1
* Minor plugin header reformatting
* Change documentation links to wp.org to be https
* Note compatibility through WP 4.0+
* Add plugin icon



git-svn-id: https://plugins.svn.wordpress.org/linkify-categories/trunk@973755 b8457f37-d9ea-0310-8a92-e5e31aec5664