Problem/Motivation
jQuery versions older than 3 are end of life.
Before we can update to jQuery 3, we need to update to jQuery UI 1.12.* because the version we're on at the moment (1.11.*) was released before jQuery 3 was available and isn't 100% compatible.
Proposed resolution
Update jQuery ui, need latest version with this patch: https://github.com/jquery/jquery-ui/pull/1751 because of https://bugs.jqueryui.com/ticket/15052#ticket
Since the compile+split is not officially supported we might want to ship the whole thing at once. Makes it easier for maintainance.
This version only supports IE11 btw.