Changes:
* Add support for a property, `IsAspNetCoreApp`, in the .csproj file of assemblies which are part of the shared framework.
* Remove unused dependencies
* Remove reference which have become part of 'netcoreapp3.0'
Changes:
* Remove obsolete targets which are unnecessary now that this repo no longer builds git submodules in a separate build process
* Remove the need for static analysis of 'ArtifactInfo' items
* Simplify how the code signing task is configured
* Remove unused repo tasks
* Remove duplicate lists of external dependencies and packages to be produced
* Remove obsolete build definition
* Remove obsolete build script parameters
* Add VisualStudioSetupOutputPath
.NET Core 2.0 reached EOL last year. This removes multi-targeting our test projects and test assets to only use .NET Core 2.1 and .NET Framework 4.6.1.
Nate McMaster
Hao Kung
Pavel Krymets
Chris Ross
Nate McMaster
Justin Kotalik
John Luo