Removes indirect group prerequisites. Removes redundant code from CharmPrerequisiteList.
Pushes AbstractGroupPrereq down into DirectGroupPrereq
Eliminates interface method that's only used internally
* To me, it's a great thing that these new classes don't need to expose their threshold values, and I'd rather not have anyone start relying on them doing it.
Removes empty interface for MultiPrerequisites
Handles character IDs in character code
Moves last remnants of "Item" to Character