* Update to 1.2.1
* Die early if script is directly invoked
* 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/post-index-helpers/trunk@973752 b8457f37-d9ea-0310-8a92-e5e31aec5664