Added code so that the mod loads dungeon packs stored in the custom
dungeons folder. Changed the code for loading bundled dungeons so that
they're loaded as dungeon packs. This means dungeon packs are now fully
integrated into the mod. The changes were tested and seem to be working
perfectly.
1. Integrated support for dungeon pack config options into the code
(i.e. we actually DO what the settings specify)
2. Added random transitions from one dungeon type to another. Dungeons
might also begin with a non-default pack.
3. Fixed a config reading bug that caused settings to be ignored and
some invalid settings wouldn't trigger exceptions. Also fixed other
dungeon pack bugs.
