There is no sync of 1.9 registration data to moodle.net's mdl_hub_site_directory table.
As of MDLSITE-2977 it is apparent there are still many 1.9 registrations coming through so we need to check on these sites.

so,this is to implement a web service call to sync 1.9 registration data back to moodle.net for link checking there.

attention will need to be paid to the 'public' field and 'privacy' field :

MOODLE_19_STABLE: (0,1,2 correspond to values of the 'public' field)
lang/en_utf8/moodle.php:1243:$string['publicdirectory0'] = 'Please do not publish this site';
lang/en_utf8/moodle.php:1244:$string['publicdirectory1'] = 'Publish the site name only';
lang/en_utf8/moodle.php:1245:$string['publicdirectory2'] = 'Publish the site name with a link';

25_STABLE:
<select name="privacy" id="id_privacy">
<option value="notdisplayed">Please do not publish this site</option>
<option value="named">Publish the site name only</option>
<option value="linked">Publish the site name with a link</option>
</select>