Change the reference scenario (for calculating the BECCS bound, see previous commit) from input_ref.gdx to the values of the own previous nash iteration.

- added documentation to the output script.
- updated the multi-comparison-matrix.
- updated the prefix used for coupled runs.
- correctly handle the number of cores to be used in parallel.

gdx neutral: clean scenarios in scenario_config_coupled_SSPSDP.csv and compareScenarios.R, add start and end time (of the job not of GAMS) to runstatistics.

Delete lusweave output files after generating runtime.pdf

move scripts for magicc into the folder core/magicc, delete outdated script performance_test.R, integrate script submit_compare.cmd into multiComparison.R