Major Improvements to DungeonHelper, Minor Bug Fixes and Tweaks

Cleaned up and rewrote some of the code in DungeonHelper. More remains to be done, but the current changes have cut the length of the code and it'll be easier to maintain in the future. We also have zero compiler warnings in DungeonHelper now. Fixed a bug that caused duplication of dungeon entries in the listing command. Made the custom dungeon loading ignore the capitalization of dungeon type tags - it was silly for us not to load dungeons if the tags differed like that. Tweaked dungeon loot generation to make DD items very slightly rarer, enchanted books slightly more common.