* Add prototype of v2 controller framework
* Add controller v2 API tests
* Remove Hash() method from controller ID interface
* Add requeue directive to controller v2 framework
* Rename 'Complete' directive to 'Ack'
* Document request directive methods
* Rename 'partitions' option to 'parallelism'
* Add controller buffer size option
* Organize files in controller v2 framework
* Fix documentation of Controller interface
* Add separate tests for each directive
* Add controller failure test
* Use structured logging in controller framework
* Fix linter errors
* Remove string formatting from formatted logging calls
* Bump version