Fixed #21940 -- Added kwargs to contribute_to_class() of model fields..

Thanks Kronuz for the suggestion.
Renamed "committers" to "team".
Removed references to partial commit acces.
Introduced a technical board.

Extended the scope of the core team a bit (depending on your current
perspective on that scope).
Documented current roles.
Left formal decisions up to the technical board.

As the core team grows towards 50 people, it isn't reasonable to give
everyone veto rights anymore.
Adjusted 'internals' docs to the new organization.

Most of these changes are about using the correct vocabulary -- "core
team member" vs "core developer/committer" and adding internal links.
Removed references to well-known political systems.

Some cultures can't handle these words.
Merge branch 'team-organization'.

https://groups.google.com/d/msg/django-developers/8b-wxEzWO3c/Hx3Uqg9XrksJ
Fixed #23103 -- Annotated ImageField file with image and content_type attributes.

Thanks Jeremy Dunck for the suggestion and Nick Sanford for review.
Fixed typo in docs/topics/testing/tools.txt.
Fixed #23108 -- Dropped support for PostgreSQL 8.4 & PostGIS 1.3, 1.4.

Thanks Claude Paroz for the review.
Removed some PostGIS 1.4 notes in the docs (refs #23108).
Fixed #7220 -- Allowed AbstractBaseUser.last_login to be null.

Thanks veena for the suggestion and Simon Charette and Kévin Etienne for reviews.
Fixed #23145 -- Dropped support for Oracle < 11.1