Various updates.
  - A Test Shadow Tigres composition has been added to test Hybrid
    factions compositons.
  - Fleets can now also be architects or cargo, not only aggressive or
    defensive.
  - Tigres and Tigers can now be used in the compos.xml, for both are
    valid spellings AFAICT.
New amount values added.
  - -1 is for unlimited.
  - 0 for “only” (for fleets of only one type of ships)
  - 6 for “one”, when it ain’t recommended to use more than a single
    ship of a particular type (for example, in anti-cargo compositions,
    or stuff like that).
  - Those special values are not to be used in common fleets. They are
    here only for very particular cases.