#241 Formula Reader should save formula string when executed

[Alexander Falenski]

I saved a new formula to a DB, loaded this formula with the formula reader and saved the workflow. Then I changed the DB, closed PMM-Lab, opened PMM-Lab again and also opened the executed Formula Reader. The new DB did not contain the formula. Strangely, the executed formula reader had a checked box next to a completely different formula. I would prefer that no box is checked when the formula which was once loaded is not present in the current DB. Would it be possible to save not only the ID of the formula but also the formula string? If both are not found no box should be checked in a workflow with an executed formula reader.