Overhauling DungeonHelper

I changed the name filter for schematic names from
CommandEndDungeonCreation to DungeonHelper, and renamed it to
NamePattern. I also rewrote most of registerCustomDungeon() to be much
more concise. The changes are incomplete but I'm making an intermediate
commit. The aim is to change DungeonHelper into a proper singleton and
to eliminate the clunky sections that manually map dungeon categories to
their corresponding lists. Instead, I'll use data structures to
implement that far more efficiently.

StevenDimDoors/mod_pocketDim/mod_pocketDim.java

@@ -177,7 +177,7 @@ public class mod_pocketDim
 		String helpFile = "/mods/DimDoors/How_to_add_dungeons.txt";
 		if(new File(helpFile).exists())
 		{
-			copyfile.copyFile(helpFile, file+"/How_to_add_dungeons.txt");
+			copyfile.copyFile(helpFile, file + "/How_to_add_dungeons.txt");
 		}
 
 		dungeonHelper.importCustomDungeons(properties.CustomSchematicDirectory);