Commented a concatenation of the old file with the new file while they had the same name; only if they span different forecast times the files should be concatenated

Bug-fix: the variable leadtime is already in the file, the dimension leadtime is not hence -v should be -d

Add automatic selection of members if list is left empty + check if prescribed members are not present (+ fixes with trap function)

Add a 'trap' command to automatically clean up the workdir (after a week) if the post-processing fails