Job completion logging from multiple clusters and sbatch script logging

Since job completion information can come from multiple clusters,
put information from each cluster into separate table ("clustername_jobcomp_table").
Otherwise the information from which cluster a specific job was submitted
would be lost.

Also added logging of the sbatch script to the same table. This is very
helpful when debugging user support cases. We have used this in production
on our clusters at the University of Tartu for about 3 or 4 months now.