SkhcConfig.DefaultSourceOperations on the .default section.
type of the default section.
section name.
name used when artist and album-artist are missing.
name used when album is missing.
name used when music's title is missing.
init ~artist ~album ~title creates a default section with artist, album and title.
default is the section used if the default section is missing from the configuration file.
of_section section parse section to create a default section. If an expected key is missing from section, the key is associated with its default value.