Initial commit of .NET port of FlatBuffers

Include C# codegen in flatc and .NET FlatBuffer access via the
FlatBufferBuilder class

Tested: on Windows.

Change-Id: If5228a8df60a10e0751b245c6c64530264ea2d8a

net/FlatBuffers/Struct.cs

@@ -0,0 +1,27 @@
+/*
+ * Copyright 2014 Google Inc. All rights reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+namespace FlatBuffers
+{
+    /// <summary>
+    /// All structs in the generated code derive from this class, and add their own accessors.
+    /// </summary>
+    public abstract class Struct
+    {
+        protected int bb_pos;
+        protected ByteBuffer bb;
+    }
+}