Fix use of Curl::$headers; add RDFDocument::subjects(); add RDFInstance::hasSubject().
Fix use of Curl::$headers; add RDFDocument::subjects(); add RDFInstance::hasSubject().

eregansu/db,eregansu/setup,eregansu/install,eregansu/silk,nexgenta/eregansu,eregansu/default,nexgenta/eregansu,eregansu/framework,eregansu/login,eregansu/lib,eregansu/eregansu,eregansu/eregansu,eregansu/gendoc,eregansu/wp-plugins