spec: Only add apache user to the icingacmd group if existing.

Refs #5263
Merge branch 'fix/spec-cmd-grp-5263' into next

Fixes #5263
core: Fix retained host check attempts being 0/1.

Refs #5061
Merge branch 'fix/retained-hst-chk-5061' into next

Fixes #5061
Update Changelog.

Refs #4815
core: Add statehistory entries for newly added services.

Refs #3854
Merge branch 'feature/statehist-svc-new-ok-3854' into next

Fixes #3854
Remove unused netutils.c

Refs #5195
Merge branch 'fix/rm-netutils-5195' into next

Fixes #5195
idoutils: wait for child processes on exit preventing zombies

Refs #4427
Merge branch 'fix/ido2db-kill-waitpid-4427' into next

Fixes #4427
Update Changelog/THANKS.

Refs #4427