Scan an assembly in order to create a DataContractContentSerializer

Resolves #100.
Agreed about only adding the code when its needed. Again, up to now I've been making an exception when it comes to the `expected` value. Now it's totally clear though – Thank you for pointing to the direction that makes this explicit!

>Is @event.AsSerializedString(actual) part of the System Under Test?

It's not – but it's the only part of the test where we actually *do* something with `actual`.

Is it part of the *Arrange* phase? No. – Is it part of the *Assert* phase? Probably not, because it's more related with the value associated with `actual`.

That's why `@event.AsSerializedString(actual)` exists in the *Act* phase...