Updated mediawiki/extensions
Project: mediawiki/extensions/SemanticSignup  3033a32d09e67ef1526b509d291e39c084025688

Rename SES_Special to SpecialSemanticSignup

Also updated file header documentation for the special page
and removed a duplicate entry for SES_UserAccountDataChecker from
$wgAutoloadClasses which originally pointed to the special page file.

Change-Id: I70a3e70024e7dfbad95608c4f563aee626211bc0