* WIP: initial data model for new meta props
* WIP: implemented new props
* test and bug fix:
- add coverage of players and sizes
- fix unlimited map size bug
* FIX: update supported players for arcade to 6
* fix: test should be min -> max, not max->max
* Change some naming and the FixedSizes function
* update comment to reflect API changes
* improve comment clarity
* rename field for improved clarity
* change some more "map" -> "board" wording
* reorganize code
* first draft of map generator interfaces
* add explicit random interface to board helpers
* implement standard map
* rename Generator to GameMap
* allow initializing snakes separately from placing them
* add random number generator to Settings
* updates to GameMap interface
* add helpers for creating and updating BoardState with maps