Pet NPC IDs break numbering convention

[joligario]

Need to identify new or additional options for assigning NPC IDs as we run out of numbers for global NPCs such as pets.

[mackal]

There are a few "official" zone IDs just under 1000 (or I think they are)

Live is currently at like 816 zones used in the client (unreleased zones)

@cream24 suggested just treating "zone ID" 2000 (so 2000 * 1000 like our current schema) as global NPCs as well.

At the end of the day, these are just conventions so we can do anything, but it's good to keep them :P

[joligario]

@mackal: I think this is resolved...?