Implement open() and closed() Maniphest tokenizer status functions, plus cleanup
Summary:
Ref T4100.
- Make it easy to choose all open or closed tasks.
- Make "special" tokenizers composable.
- Get viewer() generating documentation properly.
Test Plan:
- Ran queries with new tokens.
- Browsed new tokens.
- Viewed docs on new tokens.
- Used plain status tokens.
Reviewers: btrahan
Reviewed By: btrahan
Subscribers: chad, epriestley
Maniphest Tasks: T4100
Differential Revision: https://secure.phabricator.com/D12530