Merge pull request #662 from J-Zeitler/dev

fix a bug causing wrapped float/flex elements to flicker when sorted

Sortable.js

@@ -683,6 +683,9 @@
 
 							if (elTop === tgTop) {
 								after = (target.previousElementSibling === dragEl) && !isWide || halfway && isWide;
+							}
+							else if (target.previousElementSibling === dragEl || dragEl.previousElementSibling === target) {
+								after = (evt.clientY - targetRect.top) / height > 0.5;
 							} else {
 								after = tgTop > elTop;
 							}