* v2.3
 * New features:
 * - You can now view the average newsletter open rate from all past campaigns
 * - You can now see the newsletter open rate for that specific campaign
 * - You can now view the total number of unique newsletter opens per campaign
 * - You can now see what newsletter links each subscriber clicked on
 * - You can now see which newsletter subscribers clicked on a specific link
 * - Version check of pro in basic
 * - Styles have version numbers
 * Improvements:
 * - Newsletter statistics
 * - Changed how newsletter styles are saved in db
 * Bug fixes:
 * - Tinymce click issue

git-svn-id: https://plugins.svn.wordpress.org/sola-newsletters/trunk@952825 b8457f37-d9ea-0310-8a92-e5e31aec5664