#1 trace2dbest restarting with same data

[Mark Blaxter]

Would like toi avoid long waits for trace2dbest to delete files and then copy the same back again when rerunning trace2dbest with new parameters on the same set of data

Could have the
'Remove directory raw_traces' question to catch a 'yes' andswer, remind the user that they will be reanalysing old traces, and then NOT copy traces to 'raw_traces' in the next step.