Use WebM in copyright notice for consistency

Changes 'The VP8 project' to 'The WebM project', for consistency
with other webmproject.org repositories.

Fixes issue #97.

Change-Id: I37c13ed5fbdb9d334ceef71c6350e9febed9bbba
diff --git a/build/make/Makefile b/build/make/Makefile
index 5011ce3..1ca747a 100755
--- a/build/make/Makefile
+++ b/build/make/Makefile
@@ -1,5 +1,5 @@
 ##
-##  Copyright (c) 2010 The VP8 project authors. All Rights Reserved.
+##  Copyright (c) 2010 The WebM project authors. All Rights Reserved.
 ##
 ##  Use of this source code is governed by a BSD-style license
 ##  that can be found in the LICENSE file in the root of the source