Feature Request: Remove Unused References

[OoLunar]

Both Visual Studio and ReSharper have the ability to identify unused libraries in your csproj, while no known dotnet tool or VSC extension allows you to do so. Would be great to see the same feature available either as a command or able to set as a info/warning/error in Omnisharp's settings.

[erwinkramer]

This deserves a comment and more attention!