PHP DataHub support

PHP DataHub Support

Custom Host Name and Host ID support Key / Value pairing in log events
Being pedantic but maybe we change the ordering in this constructor to the following.

($token, $persistent, $use_ssl, $severity, $datahubEnabled, $datahubIPAddress, $datahubPort,$host_name_id_enabled,$host_name, $host_id,)

Almost maybe rename the variable to log_host_name ?