Experiment info location

The location of the file Experiment.info was wrong when doing a grid_search.py. In fact, only a single file for the entire grid search was written.

This MR fixes that by writing the Experiment.info file in the same sub-directory as the scores are written.

Furthermore, since the Experiment.info file now contains the exact command line, there is no need for the (unused) --write-commands option, which would do the same thing. Hence, this MR closes #71 (closed).