- In `CommandRegistration` add `ResolvableType` for `OptionSpec` giving
more spesific handling of a type.
- In `CommandParser` handle source and target types so that we
have generics with `List`, `Set` and arrays working better.
- In `HandlerMethodArgumentResolver` add better handling for
`ConversionService` for generic types.
- In `StandardMethodTargetRegistrar` add better types via `ResolvableType`
now that `CommandRegistration` support it.
- In `OptionConversionCommands` remove converter from `String` to `Set` as
now things should work as is if generic in a `Set` has a converter.
- Fixes#694