Closes #2893. Thanks to jwinder-ca

Closes #2885.
Closes #2881.

Thanks to everybody on those issues.

Closes #2876.

Closes #2873.

Closes #2789. Thanks to Daedaluz.

This allows us to refuse to open an existing file, without a race
condition.

This occurs when they have a will message that contains invalid property
types.

Identified by OS-TIF audit.

TOB-MOSQ-CR-5

- Broker will log warnings if sensitive files are world readable/writable, or
  if the owner/group is not the same as the user/group the broker is running
  as. In future versions the broker will refuse to open these files.

Closes #2794. Thanks to Evgeny S.

This occurred with non-matching cleansession/local_cleansession being
expired on start after restoring from persistence.

Closes #2634. Thanks to everyone on the issue.

Closes #2732. Thanks to zhousongsong.

Closes #2354.
Closes #2749.

Closes #2746. Thanks to Akos Vandra-Meyer.

Closes #2722. Thanks to KramNamez.

This could occur when built with assertions removed.

Closes #2708. Thanks to ckoehne.

and hence unchanged values disappearing. Thanks to Wim Nelis and
Christoph Krey.

Closes #2609. Thanks to JSchy65.

Currently only a single plugin can interact with a unique $CONTROL
topic. Using multiple instances of the plugin would produce duplicate
entries in the config file.

Closes #2601.
Closes #2470.

They will now not modify the client/group if a new group/client being
added is not valid, or on other failures.

Closes #2598. Thanks to Sebastian Szczepański.

Closes #2545. Thanks to p-luke.

This happens when local_cleansession is set to false and cleansession is
set to true.

Closes #2604. Thank to Frank Dekervel.