Progress on Implementing Dungeon Packs

Completed enough of the implementation and integration to compile DD.
Some portions of the code are only for testing and will be removed
later. The configuration for default dungeons is hardcoded - we can
parse config files once we're certain that dungeon chains work. At the
moment, dungeons generate but it doesn't seem like the rules we set are
being followed properly.

Renamed OptimizedRule to DungeonChainRule, and renamed the old
DungeonChainRule to DungeonChainRuleDefinition, to match the role of
each class better. Added some hax to DungeonGenerator to get packs
integrated - the implementation will be much cleaner once the new save
format is done.