Fixed NextItems logic

Replaced duplicate logic in GetChildren with MyItems
Fixed logic to check for Sections = null

PROMS/VEPROMS.CSLA.Library/Extension/ItemInsertExt.cs

@@ -725,7 +725,7 @@ namespace VEPROMS.CSLA.Library
 		{
 			get
 			{
-				if (NextItemCount > 0 && NextItems.Count > 0)
+				if (NextItemCount > 0  && NextItems != null && NextItems.Count > 0)
 					return NextItems[0];
 				return null;
 			}