Added docs/internals/mailing-lists.txt documenting the use of django's
mailing lists. All references across docs changed to point to this page.
The referencing makes use of substitution because there's no way to make
a :ref: link in a non-inline fashion in Sphinx. It also makes use of
rst_epilog Sphinx conf for making this substitutions across all the
docs.
Backport of 3895d8899d from master
This formally describes our policies on reporting, notification and
disclosure of security issues, and provides a detailed explanation of
our full security-response process, for reference purposes.
James Turley
Unai Zalakain
Claude Paroz
Russell Keith-Magee
Tim Graham
James Bennett