Support for setting the Language Version

[omajid]

I wanted to use an async Main. That requires C# 7.3. To use this, I need to set the language version. aCute doesn't provide a suggestion for adding <LangVersion>latest</LangVersion> to csproj anywhere that I can see. It doesn't even show up in the auto-completion for csproj.

[omajid]

Test program to reproduce the issue:

using System;
using System.Threading.Tasks;

namespace HelloWorld
{
    class Program
    {
        static async Task Main(string[] args)
        {
    }
    }
}

aCute doesn't even point out that there is an error, until I hit run (or debug).

[mickaelistria]

Do you get regular content-assist and so on working properly in your .cs file? It seems like this could be an issue in OmniSharp not using the right language version according to .csproj.