Add an efficiency to DnD that fixes a store problem.

There is a dstore bug that appears when a put call uses the beforeId option and the beforeId matches the id of the item being updated.  This can occur when multiple rows that are not all siblings are moved via DnD.  See issue dojo#1365.

extensions/DnD.js

@@ -105,9 +105,15 @@ define([
 					// otherwise settle for put anyway.
 					// (put will relocate an existing item with the same id, i.e. move).
 					grid._trackError(function () {
-						return store[copy && store.copy ? 'copy' : 'put'](object, {
-							beforeId: targetItem ? store.getIdentity(targetItem) : null
-						}).then(function () {
+						// Do no store operation if the object being moved is targetItem.  This can happen when
+						// multiple, non-adjacent rows are being dragged.
+						var objectId = store.getIdentity(object);
+						var targetId = targetItem ? store.getIdentity(targetItem) : null;
+						var promise = objectId === targetId ? when(true) :
+							store[copy && store.copy ? 'copy' : 'put'](object, {
+								beforeId: targetId
+							});
+						return promise.then(function () {
 							// Self-drops won't cause the dgrid-select handler to re-fire,
 							// so update the cached node manually
 							if (targetSource._selectedNodes[id]) {