v0.6.0

Changed

• The constants naming each definition's fields and enum values are associated
  constants of a type per definition, kiwi_records::NodeChange::FILL_PAINTS,
  instead of a module per definition, kiwi_records::node_change::FILL_PAINTS.
  Rust code naming them changes accordingly.
• RustQ code reaches them through KiwiCodec.RustlerGenerator.Records:
  Records.NodeChange.FILL_PAINTS and Records.Definitions.NODE_CHANGE, in a
  module that aliases it, with no defrustmod of its own. This needs RustQ
  1.0.0-rc.17.