We now track the `config_tls_refresh`, `distributed_interval` and
`logger_tls_period` flag values for each host. Each value is updated by a
detail query agains the `osquery_flags` table, because they may be specified
outside of Kolide. The flags that can be specified within Kolide are also
updated when a config is returned to the host that changes their value.
This will enable us to do a more accurate per-host online status calculation as
discussed in #1419.