* Apply Rust traits to all public types and other improvements
* Move methods into appropriate section
* Check for zero scalars
* Change element and scalar de/serialization from `GenericArray` to slice
* Customize `serde` serialization
* Introduce `Result` shorthand, re-export and rename `InternalError`
* Re-export some public API relevant types
* Move `deserialize`
* Remove branch in `i2osp`
* Make `serialize` and `serialize_owned` methods
* Update p256