closes #7721

Use markdown-it-html5-embed plugin so user can embed audio and
video using the markdown link syntax []() in the HTML5 way.

fixes #7700
closes #7706

closes #7705

The limit was added in 2012 to prevent spam, but since the participants
need to be a mutual contact with the author nowadays, I don't think it's
a spam problem anymore.

fixes #7701
closes #7702

This fixes that it fails when you call it without notes parameter.

closes #7698

closes #7642
fixes #7633

Some people may remove their birthday date after the notification was
sent, which then breaks the notification page for other users. Let's
just display the date when the notification was created, and not display
the users updated birthday date. When users update from date A to B it
always looks weird anyway, when we display the same new date B twice on
different days, or display two different dates for the same user.

We could remove notifications when users change or remove their
birthday, but that would be way more complex and also we usually don't
remove notifications (not even for deleted posts).

Fixes #7689

closes #7691

closes #7694
closes #7662
fixes #7661

closes #7684

Fixes #5727

closes #7690

Some people may remove their birthday date after the notification was
sent, which then breaks the notification page for other users. Let's
just display the date when the notification was created, and not display
the users updated birthday date. When users update from date A to B it
always looks weird anyway, when we display the same new date B twice on
different days, or display two different dates for the same user.

We could remove notifications when users change or remove their
birthday, but that would be way more complex and also we usually don't
remove notifications (not even for deleted posts).

Fixes #7689

closes #7691

closes #7683

Fixes #7679

Fixes #7681

closes #7682

closes #7656

fixes #6039

closes #7624

fixes #1649

Fixes #7651

closes #7652

The notifications need to be grouped by the same date as they are
sorted, otherwise the date used for the group doesn't match all
timestamps in the group and also the groups are sorted by the wrong
date.

This fixes #7647, a regression of #7568.

closes #7648

Cleans invalid contacts where the referenced user was deleted from the DB or where
the referenced person owner was deleted from the DB.

closes #7632

That's for the case when podmin has messed up the database

closes #7638

closes #7630

closes #7629

Relaying relayables will fail with non-lowercase authors.

closes #7625

closes #7622

closes #7617

- Removed posts and non contacts from other's data
- Collections are exported in batches to lower memory footprint
- In base exporters create User object instead of keeping instance because it caches all associations

closes #7627

It was possible to run migration locally without providing old private
key. This way migration was performed but not dispatched, which obviously
leads to desynchronization of the federation state so let's validate sender
before performing any actual actions.

closes #7558