Fixed DungeonSchematic

Modified DungeonSchematic to use the new link and dimension classes.
Fixed PocketBuilder and More

1. Changed DungeonSchematic to use an external instance of Random rather
than initializing its own.
2. Created the Pair class, a strongly-typed tuple that was needed in
PocketBuilder.
3. Added a missing calculation in NewDimData for setting the packDepth
field during dungeon initialization.
4. Finished code missing in PocketBuilder. Changes listed above were
needed for this.