This is the beginning of a migration to storing one identity
key per account, instead of the braindead duplication we're
doing now. Part one of a two-part deployment in the schema
migration process.
1) Store account data as a json type, which includes all
devices in a single object.
2) Simplify message delivery logic.
3) Make federated calls a pass through to standard controllers.
4) Simplify key retrieval logic.
