cdparanoia: try to guess a good cache size if it's set to -1

cdparanoia: try to guess a good cache size if it's set to -1

Try to guess from the paranoia-mode setting whether playback or
ripping is wanted, and use a smaller cache size if we're likely
to be doing playback, to avoid a long startup delay. Since this
was the value used in older cdparanoia versions, it should be
fine in any case. See #586331.