Update WoW plugin to build 18019.

This is tested with some dubious printf()s, and the coordinates and everything else look correct to me. I haven't managed to get it running on two different machines to verify it sounds correct. Since I've been playing WoW off and on for about 9 months I can probably commit to maintaining this a bit more often.

I am also curious as to who might use the "identity" field, and whether with the advent of cross-realm zones and cross-realm groups, it might be worth appending the realm name to the end of the player's identity.