* Added mom_onthisday (shortcode and template tag)
* onthisday displays posts from previous years that were published on the current day (and only during the duration of the current day).
* If none are found, it will display 5 random posts.
* The template function displays 5 recent years from the current category, tag, or all of the published posts on the blog (depending on whether it is being viewed on a category archive, a tag archive, or home/single view.) 


git-svn-id: https://plugins.svn.wordpress.org/my-optional-modules/trunk@806473 b8457f37-d9ea-0310-8a92-e5e31aec5664