Add a few more known NBT extensions to the file pattern for directory…

… enumeration. Closes #21.  File-based open can already handle all extensions, from #31.

NBTModel/Data/Nodes/NbtFileDataNode.cs

@@ -16,7 +16,7 @@ public class NbtFileDataNode : DataNode, IMetaTagContainer
 
         private CompoundTagContainer _container;
 
-        private static Regex _namePattern = new Regex(@"\.(dat|nbt|schematic)$");
+        private static Regex _namePattern = new Regex(@"\.(dat|nbt|schematic|dat_mcr|dat_old|bpt|rc)$");
 
         private NbtFileDataNode (string path, CompressionType compressionType)
         {