Improve debug commands

[seanohue]

Some ideas:

• debugitem <item> and debugchar <character> would show all stats/flags/internals of an instance of an entity, in a way that is formatted to be somewhat readable.

• debugeffects [entity] would do a similar thing but for the effects on the player using the command, or optionally, a targeted entity such as an NPC.

• showall [npcs, items, rooms, players] would list all of a certain kind of entity (or just all entities, if not given a parameter) that are currently loaded into the game world.

• teleport <roomID> allows for instant travel to a room if given a valid ID.