Add a function that removes unwanted items from the database at regular intervals
|Reported by:||Nicklas Nordborg||Owned by:||Nicklas Nordborg|
Unwanted items are:
- Stray any-to-any links (see #1340)
- Unused item and project keys
The cleanup should be executed at regular intervals (possible configurable). It should be possible to disable this function since we don't want to execute it from job agents.