Xsdata

- Added support xs:any and xs:anyAttribute elements.
- Added support for auto-detecting XML Schema namespace prefix.
- Added support for xml datatypes lang and base.
- Refactored SchemaParser to use the XmlParser.
- Updated XmlParser to bind after elements are fully parsed.

- Fixed elements min|man occurs inheritance from their container.
- Fixed global elements and attributes are now always qualified.
- Fixed including no namespace schemas.
- Fixed list elements attribute handling.
- Added support for unqualified elements.
- Added support for qualified attributes.
- Added support for nillable elements.
- Added support for unions of member and simple types.
- Added binding test suite

- Generate anonymous Enumerations
- Generate attributes from List and Union elements
- Fix restriction inheritance
- Officially support python 3.8
- Completely migrate to setup.cfg
- Introduce integration test suite

- Change print mode to print rendered output
- Added new format PlantUML class diagram to replace the old print/debug mode

- Initial release