Mostly adds styles for lists and mediaelement.js instances within widgets.
Adds size classname to image widget so themes can customize their display.
Props Soean, obenland, celloexpressions, ocean90, karmatosed.
Fixes#40745.
Built from https://develop.svn.wordpress.org/trunk@40839
git-svn-id: http://core.svn.wordpress.org/trunk@40690 1a063a9b-81f0-0310-95a4-ce76da25c4cd
The last time a new widget was introduced, Vuvuzelas were a thing, Angry Birds started taking over phones, and WordPress stopped shipping with Kubrick. Seven years and 17 releases without new widgets have been enough, time to spice up your sidebar!
Props westonruter, melchoyce, obenland, timmydcrawford, adamsilverstein, gonom9, wonderboymusic, Fab1en, DrewAPicture, sirbrillig, joen, matias, samikeijonen, afercia, celloexpressions, designsimply, michelleweber, ranh, kjellr, karmatosed.
Fixes#32417, #39993, #39994, #39995.
Built from https://develop.svn.wordpress.org/trunk@40640
git-svn-id: http://core.svn.wordpress.org/trunk@40501 1a063a9b-81f0-0310-95a4-ce76da25c4cd
