Generate partial C# classes for WellKnownTypes

[Sigurt Dinesen]

The C# reference (https://developers.google.com/protocol-buffers/docs/reference/csharp-generated#structure) makes it seem like the classes in WellKnownTypes should be partial,

just like those generated from custom proto files.
However, they are not.
Is this intentional or a mistake?
Or am I Just missing something? :)

Concretely, I'm looking to extend the wellknown types /such as StringValue) with implicit conversions to and from .NET types.
I can do this for generated types (because they are partial), but not for the well known types.

Best, Sigurt.