= 1.5.4 =
* Added AJAX search support on notifications list posts filter
* Added improve LD posts selector logic especially for site with big number of courses, lessons, etc
* Added change post selectors in notification metabox to use select2 and dynamic AJAX options
* Updated update LearnDash strings using LD custom label
* Updated use learndash_quiz_submitted action hook instead of learndash_quiz_completed
* Fixed make sure retrieved group leaders has group leader role
* Fixed before course expires notification is sent before set value