Bump version in doc/conf.py.
Remove version number in doc/conf.py.

Fixes #6222
Build fix for Windows.

Refs# 6191
Fix crash when zones.d directory doesn't exist.

Fixes #6224
Set parent_host_name in Dependency objects to the host's name for apply rules.

Fixes #6197
Fix incorrect chapter titles.

Refs #5795
Add check command for check_dhcp.

Refs #6225
Execute apply/object rules in parallel.

Fixes #6223
Simplify "ignore where" condition in the example config.

Refs #5795
Parallellize restoring objects from the state file.

Fixes #6226
Implement support for overriding the version number.

Fixes #5410
Implement the ICINGA2_GIT_VERSION_INFO option.

Refs #5410
Proof of concept how a real reload-handling with systemd could work.

Refs #6118
Unlink the pidfile when we really shutdown (not reload).

Refs #6118
Add Process::GetPID and make it work on Unix and Windows.

Refs #6118
Merge branch 'feature/systemd-reload-6118' into next

Fixes #6118
Documentation: Classic UI command expander feature does not work using Icinga 2.
Remove duplicate information in INSTALL file.
Fix deadlock in db_ido.

Fixes #6230
Bump version for next release target.

Refs #6231