upgrade third_party/protobufs to 3.0.0-beta-1
diff --git a/vsprojects/build_plugins.bat b/vsprojects/build_plugins.bat
new file mode 100644
index 0000000..4c33a58
--- /dev/null
+++ b/vsprojects/build_plugins.bat
@@ -0,0 +1,23 @@
+@rem Convenience script to build gRPC protoc plugins from command line. protoc plugins are used to generate service stub code from .proto service defintions.
+
+setlocal
+
+@rem enter this directory
+cd /d %~dp0
+
+@rem Set VS variables (uses Visual Studio 2013)
+@call "%VS120COMNTOOLS%\..\..\vc\vcvarsall.bat" x86
+
+@rem Build third_party/protobuf
+msbuild ..\third_party\protobuf\cmake\protobuf.sln /p:Configuration=Release || goto :error
+
+@rem Build the C# protoc plugins
+msbuild grpc_protoc_plugins.sln /p:Configuration=Release || goto :error
+
+endlocal
+
+goto :EOF
+
+:error
+echo Failed!
+exit /b %errorlevel%