libprotobuf for Unreal Engine 4

Link the google's protocol bufffers library as the third party in Unreal Engine 4.

Prerequisites

Python v3 (for install and build scripts)
depending on you building platform:
- Windows: CMake and either Visual Studio 2015 or Visual Studio 2017
- Linux: clang and Unreal Engine Source Code

Clone or add this repository as submodule to your project directory.
Go into the just created directory and run ./install.py. This will build protobuf and copy the compiled version into the ThirdParty directory of your project (<your project>/Source/ThirdParty/libprotobuf).
Add the libprotobuf as a module into <your project>.Build.cs

PrivateDependencyModuleNames.AddRange(new string[] { "CoreUObject", "Engine", "libprotobuf" });

Generate protobuf code files (header & source, ex: Message.pb.h & Message.pb.cc) of your protocol files (.proto) by protoc for cpp (The protoc executable is located in <your project>/Source/ThirdParty/libprotobuf/bin). (Ref: Google's Protocol Buffers)
Put the resulting files into the source directory of your project.
Regenerate these code files for Unreal Engine 4 by regenerateforue4.py.
- python regenerateforue4.py Message.pb.h
- python regenerateforue4.py Message.pb.cc
- You should get this information: Success to regenerate the code for UE4
Include and use the header file (ex: Message.pb.h) in your .cpp file.
That's all.