Allow providing additional SLURM parameters via cfg$slurmConfig. Parameters that are later provided interactively via start.R overwrite the cfg values. Closing #139

Introduce the option to send output scripts for single runs to the cluster (comparison scripts will follow later)

Refactoring start scripts: - moved the definition of the slurm strings from  submit() in submit.R to choose_submit() in start.R
- renamed the function choose_submit() to choose_slurmConfig() and moved it to the new file choose_slurmConfig.R