Split "authors" and "maintainers" into finer-grained contributions

[robotlolita]

Instead of a single "authors" field we could have:

• implementation_contributors — for people who've contributed to the implementation of the functionality.
• documentation_contributors — for the people who've contributed to the documentation of the functionality.
• test_contributors — for the people who've contributed tests for the functionality.

Instead of a single "maintainers" field we could have:

• implementation_maintainers — for the people who maintain the functionality.
• documentation_maintainers — for the people who maintain the documentation.
• test_maintainers — for the people who maintain the tests of the functionality.

[vendethiel]

why?

[robotlolita]

Proper crediting is the major reason, I suppose. For the maintainers, letting people know who to talk to for particular areas of the project.