Account table refactoring

- Remove the account columns (type, name, data_set) from the
raw_contacts/groups tables and add account_id instead.

- Re-create the accounts table.  The new table now has the _ID column.  Rows
in this table now has a different lifecyle than before:
-- New row is created as the provider detects a new account during a write
operation to the raw_contacts and groups table.
-- Stale rows are removed upon account removal.

- Removed account consistency check for steam items/photos.  We don't do this
kind of check for other tables.

Change-Id: I1ce01590aef70f417fa89426dae762a41d25d656
10 files changed