Fix parsing of split petrol transactions

A petrol transaction might look like below due to the raised "4)" letters in
the original PDF.

2014-05-14      NORRK STHLMSVÄG             4)
                                             95 OKTAN             29,53       14,43       85,22            426,12         426,12

This case needed some adjusments to treatment of continuation lines in the
to_csv.awk script.