Convert 'msvs_prebuild' and 'msvs_postbuild' for MSBuild (Visual C++ 2010).

test/msvs/buildevents/buildevents.gyp

Index: test/msvs/buildevents/buildevents.gyp
===================================================================
--- test/msvs/buildevents/buildevents.gyp	(revision 0)
+++ test/msvs/buildevents/buildevents.gyp	(revision 0)
@@ -0,0 +1,14 @@
+# Copyright (c) 2011 Google Inc. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+{
+  'targets': [
+    {
+      'target_name': 'main',
+      'type': 'executable',
+      'sources': [ 'main.cc', ],
+      'msvs_prebuild': r'echo starting',
+      'msvs_postbuild': r'echo finished',
+    },
+  ],
+}