netstandard API contracts and surface area

Find these at https://apisof.net/catalog

To see whether a specific class or class member is supported, drill down to its page. For instance, see the version support for HttpWebRequest.Timeout at this URL: https://apisof.net/catalog/System.Net.HttpWebRequest.Timeout

See also:

• https://github.com/dotnet/standard/blob/master/docs/versions/
• https://docs.microsoft.com/en-us/dotnet/articles/standard/library
• https://docs.microsoft.com/en-us/dotnet/core/api/
• http://stackoverflow.com/a/42685492/1108891