IReadOnlyList and IReadOnlyDictionary support
Duplicated List/Dictionary tests for IReadOnly* versions

And this led to some fixes for missing serializing/deserializing
Merge branch 'master' into read-only-interfaces
Merge branch 'read-only-interfaces' of github.com:manofstick/Jil into pr-68
fix a verification bug in the DEBUG build around read-only lists