Closes #2855. Thanks to cfi-gb

Closes #2839. Thanks to KaeLL

Closes #2867

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.

Fix engine keyfile support.

Closes #2799. Thanks to n00b42

Do not add outgoing bridge connection context to session expiry list

Fix sub_count is not decreased when client ubsubscribe

man: Fix typo-in-manual-page noticable noticeable

This was reported by debian lintian checker

Forwarded: https://github.com/eclipse/mosquitto/pull/2846#OpenSigned-off-by: NPhilippe Coval <rzr@users.sf.net>

git: Ignore more generated files

Signed-off-by: NPhilippe Coval <rzr@users.sf.net>

Signed-off-by: NNorbert Heusser <norbert.heusser@cedalo.com>

Signed-off-by: Nlinkkzz <jk588592@163.com>

Do not try to open keyfile when keyform is "engine": this is not necessarily a real file.
Dynamic engines require init with OPENSSL_INIT_ENGINE_DYNAMIC before they can be loaded.
Signed-off-by: NBart Desplanques <bart.desplanques@gmail.com>

Closes #2794. Thanks to Evgeny S.