- allow mixed parsed body for Transfer attribute

- new attribute IdentifiableValueListLoad

- fix for documentation typos

- default producer for mangled and unsupported 'Accept' headers

- build-in producers no longer generate empty response body for null
- custom message for 400, 401 and 403 http exceptions moved to response body
- dependency update

- documentation update

- compatibility fix: now it is possible to declare several custom HTTP methods for single handler method using PHP attributes just like using annotations
- minor dependency updates

Minor dependency update for official PHP 8.0 support

Documentation update for new version

- support for DataTransfer 0.3

- test on PHP 7.4 via Travis

- fix for PHP version check in Travis CI build

- added information about router factories in docs