Released to CTAN today: most notable change is the message formatting.

### Added

- `\g_msg_module_documentation_prop` (see #471)
- `\peek_remove_spaces:n`

### Changed

- Formatting of messages: now follows LaTeX2e closely

### Deprecated

- `\mg_interrupt:nn`, `\msg_log:n` and `\msg_term:n`

### Fixed

- Handling of inheritance for choice keys (fixes #483)