List all users.

def acp_users():
    """List all users."""
    if not current_user.is_admin:
        return error("Not authorized to edit users.", 401)
    if not db:
        return error('The ACP is not available in single-user mode.', 500)

    alert = ''
    alert_status = ''
    if request.args.get('status') == 'deleted':
        alert = 'User deleted.'
        alert_status = 'success'
    if request.args.get('status') == 'undeleted':
        alert = 'User undeleted.'
        alert_status = 'success'

    uids = db.hgetall('users').values()
    USERS = sorted([(int(i), get_user(i)) for i in uids], key=operator.itemgetter(0))
    return render('coil_users.tmpl',
                  context={'title': 'Users',
                           'USERS': USERS,
                           'alert': alert,
                           'alert_status': alert_status,
                           'delform': UserDeleteForm(),
                           'editform': UserEditForm(),
                           'importform': UserImportForm()})