Fix incorrect value for the triggered_by_id column.

Fixes #5279
Improve error messages for the check result reader.

Fixes #5275
Just write objects.cache file once.

Fixes #5270
Fix duplicate IDs in queries for comments/downtimes.

Fixes #5283
ScriptVariableRegistry::GetInstance should not be defined inline.

Fixes #5284
Fix syntax error in mail-notification.sh.

Fixes #5285
Fix deadlock in ServiceDbConnect::Add{Comments,Downtimes}.

Fixes #5286
Fix missing comment_data column in downtime tables.

Fixes #5282
Improve compatibility with Windows.

Fixes #5287
NSCA-ng Vagrant Support: add nsca user to icingacmd group, move nsca-ng
config files and set appropriate file permissions.

Fixes #5222