Add more details to info.json

[lang-m]

It would be useful to also save the end time (and for convenience maybe the elapsed time) to the info.json file after the simulation has finished successfully. That way users know

• how long the simulations took
• which simulations finished successfully (which would be very useful when interrupting "bad" simulations in more interactive, exploratory simulations)

[fangohr]

That kind of information ("did the job finish succesfully") is also good to restart jobs that failed for other reason, say the HPC resource failed, job ran out time, etc. In particular, where one wants to do this automatically for a larger number of jobs.