Warnings removed & Windows support

Hello, I added Windows support to your library. (Checked and working).

I am creating a Telegram Client for Sailfish OS and I started wrapping telegram-cli but this way was unmaintainable. I found your Qt library and looks good, so I would like to start using it.

At this moment I only can use Windows on my machine so I would like to test the code firstly on Windows. This is why I fixed the project for support Windows.

Tested on Windows 10 with Visual Studio 2013 x64.