issue 6 solved. recalculate balance is scheduled as a ajax task from /shared/user_div partial for friends with old balance

 6) batch processing:
    accept new deal - set new_balance_at = yesterday - for both users - user is marked for recalculate balance (ok)
    batch processing - recalculate balance for all users where new_balance_at != today (todo)
    or recalculate balance for users with old balance in an ajax task
    page - catch all user ids with old balance in an array and schedule recalculation as an ajax task