fix pipe support on windows

STDIO streams are opened in text mode by default on Windows. This patch
changes the stdin/stdout streams to be in binary mode if they are being
used for I/O from the vpxenc or vpxdec tools.

Fixes issue #216. Thanks to mw AT hesotech.de for the fix.

Change-Id: I34525b3ce2a4a031d5a48d36df4667589372225b

tools_common.c

@@ -0,0 +1,24 @@
+/*
+ *  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
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+#include <stdio.h>
+#include "tools_common.h"
+#ifdef _WIN32
+#include <io.h>
+#include <fcntl.h>
+#endif
+
+FILE* set_binary_mode(FILE *stream)
+{
+    (void)stream;
+#ifdef _WIN32
+    _setmode(_fileno(stream), _O_BINARY);
+#endif
+    return stream;
+}