Library, Step 1

[Wohlstand]

This is a small commit where I fixed the QMake build on Windows.

As we discussed here, I will send you a sequence of pull-requests based on my library-3 branch. I will send the next once you merge this. And then, continue this until all commits from the library-3 will reach you.

[bisqwit]

What is the reason for changing from C++11 to C++17 in the commit?

[Wohlstand]

What is the reason for changing from C++11 to C++17 in the commit?

I don't remind why I did that, but as I remind, I got some errors/warnings when I built this on Windows. I should try to check this again and tell what is a reason of this failure...

[Wohlstand]

Or wait... I remind that you specified in your Makefile the c++1y, and I though it was C++17, but it was actually C++14. But, I'll test the build on my end first, and then I'll tweak this case.

[Wohlstand]

Okay, I see, the C++17 is required because of the std::string_veiw being used by you in the code. With C++14 the build fails. The std::string_view is a part of C++17 standard: https://en.cppreference.com/w/cpp/header/string_view