Modified click and touchstart events to support shift key event , not is...

Modified click and touchstart events to support shift key event , not is possible to multiselect values keeping shift pressed

js/bootstrap-multiselect.js

@@ -283,6 +283,34 @@
 
             $('li a', this.$ul).on('touchstart click', function(event) {
                 event.stopPropagation();
+
+                if ( event.shiftKey) {
+                    var checked = $(event.target).prop('checked') || false;
+                    if ( checked ) {
+                        var prev = $(event.target).parents('li:last')
+                            .siblings('li[class="active"]:first');
+
+                        var currentIdx = $(event.target).parents('li').index(),
+                            prevIdx = prev.index();
+
+                        if ( currentIdx > prevIdx ) {
+                            $(event.target).parents("li:last").prevUntil(prev).each(
+                                function() {
+                                    $(this).find("input:first").prop("checked", true).trigger("change");
+                                }
+                            );
+                        } else {
+                            $(event.target).parents("li:last").nextUntil(prev).each(
+                                function() {
+                                    $(this).find("input:first").prop("checked", true).trigger("change");
+                                }
+                            );
+                        }
+                    }
+                }
+
+
+
                 $(event.target).blur();
             });