add copyrights on csharp

runtime/CSharp/runtime/CSharp/Antlr4.Runtime/RuleDependencyAttribute.cs

@@ -1,4 +1,9 @@
-namespace Antlr4.Runtime
+/* Copyright (c) 2012 The ANTLR Project Contributors. All rights reserved.
+ * Use is of this file is governed by the BSD 3-clause license that
+ * can be found in the LICENSE.txt file in the project root.
+ */
+
+namespace Antlr4.Runtime
 {
     using System;
 

runtime/CSharp/runtime/CSharp/Antlr4.Runtime/RuleVersionAttribute.cs

@@ -1,4 +1,9 @@
-namespace Antlr4.Runtime
+/* Copyright (c) 2012 The ANTLR Project Contributors. All rights reserved.
+ * Use is of this file is governed by the BSD 3-clause license that
+ * can be found in the LICENSE.txt file in the project root.
+ */
+
+namespace Antlr4.Runtime
 {
     using System;
 

runtime/CSharp/runtime/CSharp/Antlr4.Runtime/Sharpen/Compat/SerializableAttribute.cs

@@ -1,4 +1,9 @@
-#if PORTABLE
+/* Copyright (c) 2012 The ANTLR Project Contributors. All rights reserved.
+ * Use is of this file is governed by the BSD 3-clause license that
+ * can be found in the LICENSE.txt file in the project root.
+ */
+
+#if PORTABLE
 
 namespace System
 {

runtime/CSharp/runtime/CSharp/Antlr4.Runtime/Sharpen/SequenceEqualityComparer.cs

@@ -1,4 +1,9 @@
-namespace Antlr4.Runtime.Sharpen
+/* Copyright (c) 2012 The ANTLR Project Contributors. All rights reserved.
+ * Use is of this file is governed by the BSD 3-clause license that
+ * can be found in the LICENSE.txt file in the project root.
+ */
+
+namespace Antlr4.Runtime.Sharpen
 {
     using System.Collections.Generic;
     using System.Linq;