• fix for griditems with x=0 placement wrong order (introduced by #1017) (#1054).
• fix cellHeight(val) not working due to style change (introduced by #937) (#1068).
• add gridstack.poly.js for IE and older browsers, removed core-js lib from samples (<1k vs 85k), and all IE8 mentions (#1061).
• add jquery-ui.js (and min.js) as minimal subset we need (55k vs 248k), which is now part of gridstack.all.js. Include individual parts if you need your own lib instead of all.js
  (#1064).
• changed jquery dependency to lowest we can use (>=1.8) (#629).