Need to review our mechanism for ensuring API compatibility

[jonpryor]

I'm starting to doubt the reliability of our API compatibility infrastructure which uses mono-api-info.exe, mono-api-html.exe, and the xamarin-android-api-compatibility repo.

What do the mono and corefx repo's do to ensure API compatibility?

Should we do what they do?

[jpobst]

This has been replaced with ApiCompat from the dotnet repo.

#3884