v0.8.0

Changed

• The genome level's first resolution is now family, not unordered. It is the default
  resolution and the first thing a new user meets, and it was named for the feature it lacks rather
  than for what it is. The other two resolutions keep their names, and the model itself is untouched —
  the three still share one engine, one rate grammar and one event log. This is a breaking rename
  with no deprecation aliases:

  was	is
  simulate_genomes_unordered(…)	simulate_genomes_family(…)
  GenomesResult	FamilyGenomesResult
  UnorderedGenome	FamilyGenome
  genomes.unordered(…)	genomes.family(…)
  zombi2.genomes.unordered	zombi2.genomes.family
  --resolution unordered, and the same value in a --params file	--resolution family

  Renaming the result class also removes an asymmetry: the first resolution returned the unprefixed
  GenomesResult while its two siblings carried a prefix, which read as a default plus two variants
  rather than three resolutions of one model. The run log's resolution row and the run-completion
  summary now say family; no output filename, directory or column header changes, so nothing that
  reads a run's tables needs updating. Chapter 4 is now Genomes I: gene families. (#245)

• families= is now family_names=, on simulate_genomes_family, simulate_genomes_ordered and
  genomes.family(…); zombi2 joint --families is likewise now --family-names. The argument takes a
  list of names and always did — the attribute it fills has been result.family_names all along — so
  input and output now agree, and initial_families=100 (a count) no longer reads as a sibling of the
  name list beside it. (#245)