Extending the Reference Manager needs additional documentation and support.

[kfertitta]

We have a custom CPS project system which has a couple of custom reference types. Consequently, we would like to add custom tabs for displaying and manipulating our custom reference types. We've relied on Reflector to see how some of the custom reference providers are implemented, but it's not exactly straightforward. More crucially, there's some additional infrastructure needed.

1. The are at least two assemblies that must be referenced by our extension in order to author our own reference providers:

• Microsoft.VisualStudio.ReferenceManager.Contracts.dll
• Microsoft.VisualStudio.ReferenceManager.Providers.dll

These are not available in the VSSDK nor in NuGet, making it difficult to deal with for CI builds.

2. There are no binding redirects for the Reference Manager assemblies in devenv.exe.config. We build a single VSIX that references the lowest VS version we support (currently VS2017), and we need a binding redirect in place for that to run in VS2019. Injecting those redirects via a custom .pkddef in our vsixmanifest doesn't work because we cannot conditionally deploy a VsPackage type of Asset via the TargetVersion attribute. The lack of a binding redirect is a blocking issue for this scenario.