Remove or move Cygwin Instructions from the user manual

[jan-cerny]

We enabled to build OpenSCAP on Windows using Microsoft Visual Studio 2017. I think this will be the preferred way for our contributors who will contribute on Windows.

Do we want to keep the instructions that say it is best to build it without probes using Cygwin?

https://github.com/OpenSCAP/openscap/blob/master/docs/manual/manual.adoc#building-openscap-on-windows

I suggest removing these or at least moving them down so that Building Using Visual Studio section is visible at first place.

https://github.com/OpenSCAP/openscap/blob/master/docs/manual/manual.adoc#67-building-openscap-on-windows-using-visual-studio

What is your opinion on this topic?

[jan-cerny]

Maybe it would be better if I provide a PR where I will show my vision and then we would discuss on that PR.

[jan-cerny]

I suggest continuing this discussion in #1080

[jan-cerny]

Fixed in #1080