This is saved in a SQLite database inside the user config directory named

contacts.db. It does its best to synchronize with PurpleBuddy, but not

everything emits a signal when it changes.
Also, stuff like custom avatars are ignored as those are currently store

on the Contact and we don't have a mapping to PurplePerson yet.

Ran with the demo account and verified everything about the contacts was stored via the sqlite3 command line.