Nicer view and documented

• Better input format documentation
• Person box redesigned:
  • Name on top, below surname, smaller and dimmer
  • remove spurious margins
  • always born and died on the left and right halves
  • Stillborn symbol when born: false
• Unions:
  • Bigger family bullet
  • Children node is a small turned triangle
  • Married and divorded dates are not exclusively displayed
  • Less chaotic children links
• Subcommand scheme to generate the schema.
• Fix: Person box is a link to person.link[0] if specified
• Fix: Person classes styles are now applied
• Fix: Undetailed persons are warned but properly handled
• Some test coverage added