Added IPackable interface

TShockAPI/IPackable.cs

@@ -0,0 +1,43 @@
+/*   
+TShock, a server mod for Terraria
+Copyright (C) 2011 The TShock Team
+
+This program is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Linq;
+using System.Text;
+
+namespace TShockAPI
+{
+    /// <summary>
+    /// Derived objects can be written to and read from streams.
+    /// </summary>
+    public interface IPackable
+    {
+        /// <summary>
+        /// Writes object information to the stream
+        /// </summary>
+        /// <param name="stream">Stream to write to</param>
+        void Pack(Stream stream);
+        /// <summary>
+        /// Reads object information from the stream
+        /// </summary>
+        /// <param name="stream">Stream to read from</param>
+        void Unpack(Stream stream);
+    }
+}