Support serialisation of IReadOnlyList<T> and IReadOnlyCollection<T>

[drewnoakes]

Currently an exception is thrown if attempting to create a serialiser for a type that has a field of IReadOnlyList<T>.

IList<T> is supported. Is there any reason a read only list couldn't be supported too?

[yfakariya]

Because it was not required. And historically, I has not supported ".NET 4.5" only features so aggresively. I will add them to default collection of SerializationContext by default.

[drewnoakes]

Thanks for your reply. I put together a PR for this that hopefully makes it easier for you to add this feature.