Merge pull request #2 from thePrincipal/feature/Issue-347

Add fix for null itemScope

Author: thePrincipal

source/sortable-helper.js

@@ -226,7 +226,7 @@
             targetElementOffset: null,
             sourceInfo: {
               index: item.index(),
-              itemScope: item.itemScope,
+              itemScope: ( item.itemScope || item ),
               sortableScope: item.sortableScope
             },
             canMove: function(itemPosition, targetElement, targetElementOffset) {