Knack

++++++++
* Add a `default_value_source` property in `HelpParameter` (202)
* Support removing option/section from config file (201)
* Support writing comment to config file (201)
* Import `configparser` directly instead of from `six` (201)
* Drop `get_config_parser` function from `config.py` (201)

++++++++
* Change the timing to raise `EVENT_CLI_POST_EXECUTE` event (199)
* Make `CLI.invoke` catch `SystemExit` (199)

++++++++
* Change experimental tag color to cyan (196)

++++++++
* Allow disabling color (171)
* Support yaml and yamlc output (173)
* Drop support for python 2 and 3.5 (174)
* Support ``--only-show-errors`` to disable warnings (179)
* Add experimental tag (180)

+++++
* Fix bug where arguments in preview did not call registered actions. This meant that parameter parsing did not behave
completely as expected.

+++++
* Adds ability to declare that command groups, commands, and arguments are in a preview status and therefore might change or be removed. This is done by passing the kwarg `is_preview=True`.
* Adds a generic ``StatusTag`` class to ``knack.util`` that allows you to create your own colorized tags like ``[Preview]`` and ``[Deprecated]``.
* When an incorrect command name is entered, Knack will now attempt to suggest the closest alternative.