(cherry picked from commit 9f5628d)
Re-tested briefly on 20.03.  /cc PR #94421.

There is no extra security properties provided by sha512, they are
just bigger.

(cherry picked from commit f84cd5f)

(cherry picked from commit 11acd8b)

(cherry picked from commit e97bd70)

(cherry picked from commit 8b893ec)

(cherry picked from commit 29c38ef)

(cherry picked from commit 2409432)

/cc the last PR #94421.  I ran each for a minute or two.

That way the name can make sense without being changed often.

It's exactly code written for nixpkgs master (over multiple commits),
except that gyp is used from python2 as the version in nixpkgs 20.03
refuses to work with python3.

Changelog: https://github.com/unicode-org/icu/releases/tag/release-67-1
(cherry picked from commit 878ed3e)

Later firefox versions won't build with the current nodejs;
it's just build-time dependency and 13 seems to work fine.

(cherry picked from commit d4e479a)
/cc original PR #92043.

(cherry picked from commit 1d730e1)
/cc master PR #94421.

We've been slipping behind on backporting for the default
firefox version.  This doesn't make it perfect, but using ESR 78
should make it easier for us to keep up.

Certainly feel free to work on backporting 79+ as well.

I briefly tested both affected versions (68 and 78).

See NixOS/nixpkgs@c5dd1fb#commitcomment-41126603

(cherry picked from commit 3c155bb)

PostgreSQL is listed as an officially supported database backend.

(cherry picked from commit 1bee476)

[20.03] mautrix-telegram: add postgresql database driver