Improve robustness

[MaCuinea]

No sys.exit() but try to wait for input or ask user for input. For example, file not found, ask for other file.

Maybe even add a resume button: If the measurement is stopped for some reason, restart the program and thick the Resume measurement box. We append the raw file and the csv file based on the last recorded coordinate (written in the log folder) and starts the measurement (based on the original coordinate file at the last recorded coordinate)... result of the measurement files at completion will be the same.