Fix for angular-ui#753: sortable not working in IE11

Originally from: szsolt@a274f49

Author: pgrm

README.md

@@ -1,3 +1,7 @@
+Simple fork of [angular-ui/ui-select](https://github.com/angular-ui/ui-select) with some additional fixes:
+
+- Fixed [angular-ui#753](https://github.com/angular-ui/ui-select/issues/753) ([commit](https://github.com/szsolt/ui-select/commit/a274f49122c522bb8621e5f2cb701344c5164e69), [PR](https://github.com/angular-ui/ui-select/pull/1121/files))
+
 # AngularJS ui-select [![Build Status](https://travis-ci.org/angular-ui/ui-select.svg?branch=master)](https://travis-ci.org/angular-ui/ui-select)
 
 [![Gitter](https://badges.gitter.im/Join%20Chat.svg)](https://gitter.im/angular-ui/ui-select?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge)

src/uiSelectSortDirective.js

@@ -31,7 +31,7 @@ uis.directive('uiSelectSort', ['$timeout', 'uiSelectConfig', 'uiSelectMinErr', f
       element.on('dragstart', function(e) {
         element.addClass(draggingClassName);
 
-        (e.dataTransfer || e.originalEvent.dataTransfer).setData('text/plain', scope.$index);
+        (e.dataTransfer || e.originalEvent.dataTransfer).setData('text', scope.$index.toString());
       });
 
       element.on('dragend', function() {
@@ -63,7 +63,7 @@ uis.directive('uiSelectSort', ['$timeout', 'uiSelectConfig', 'uiSelectMinErr', f
       var dropHandler = function(e) {
         e.preventDefault();
 
-        var droppedItemIndex = parseInt((e.dataTransfer || e.originalEvent.dataTransfer).getData('text/plain'), 10);
+        var droppedItemIndex = parseInt((e.dataTransfer || e.originalEvent.dataTransfer).getData('text'), 10);
 
         // prevent event firing multiple times in firefox
         $timeout.cancel(dropTimeout);