Update version for the NuGet packages to 3.0.0

- Update State of Development
- Update release build references

Package runtime DLLs for NuGet

Remove fedora-x64 as NuGet target, as linux-x64 is preferred now

Build shared libraries on Windows

Update CSFML version to 2.6.1

Update CSFML to 2.6.0

Update CSFML version to 2.5.2

Update CSFML version to 2.5.1

- Add macOS build script
- Update existing nuget build script

Merge pull request #130 from DemoXinMC/master

sfText_getLineSpacing is not properly declared in Text.h

Merge pull request #120 from crumblingstatue/master

Add setVirtualKeyboardVisible