title: Add build number to package version with `dotnet pack` in VSTS Build process
body: <p>With a .NET Framework library you could specify a version with a wildcard and NUGET pack command would append the build date and version automatically when running a NUGET Build Task in VSTS.</p>
  
  <p><code>[assembly: AssemblyVersion("1.0.*")]</code></p>
  
  <p>NUGET PACK would generate a NUPKG file with a version like <code>1.0.6604.1234</code> appending the date number and a build ID.</p>
  
  <h3>NET Standard issues</h3>
  
  <p>In .NET Core and .NET standard the new <code>.csproj</code> format does not support this wildcard format.</p>
  
  <p>We can't package with Nuget.exe (reason: <a href="https://github.com/dotnet/standard/issues/481" rel="noreferrer">this issue</a>) but we can use <code>dotnet pack</code>  except I need to auto-increment the build numbers. The <code>dotnet</code> Build Task in VSTS allows me to wholly replace the version number, but I want to retain the version in the csproj file, and just append a build number (as I used to).</p>
  
  <p>I found that using <code>&lt;VersionPrefix&gt;x.y&lt;/VersionPrefix&gt;</code> in the csproj file would work with <code>nuget pack</code> and I could then add the additional parameter <code>VersionSuffix=$(Build.BuildNumber)</code> to the pack task. </p>
  
  <p>All looked good until the first dev updated the project version in the project properties dialog. Visual Studio ignored the VersionPrefix and set the <code>&lt;Version&gt;</code> tag - and the build number fix is ignored because a <code>Version</code> tag exists.</p>
  
  <p>Is there a way to read the <code>Version</code> from the csproj? If so I could set the build property to <code>Version=$(ProjectVersion).$(Build.BuildNumber)</code> ?</p>
  
  <p>Or are there alternative ways to handle auto-incrementing the build version when packaging?</p>