Add support for dynamic token rings to the optional token image mapping.
Changed Troops to be represented by default by 16 1x1 tokens.
Added a toggleable feature (defaults to on) to use the crew art (4 x 4 copy of the token art with a frame) for the example crews in the compendium.
Added a blank token frame, and centre decoration only token frames as an option to limit clashing with the dynamic token ring.