Release note for versions 1.60 and 1.70:

* No change in features.

* Additional arguments are now specified when calling FFMPEG
   and WAV metadata skipping has been implemented
   to avoid having the norqualized audio starting with disgracious "pops".
   (These unwanted pops could also flaw the normalization).

* Bug fix (1.70): When working on a single source file, the process could hang.
