fix "No page-level DocBlock"

lib/public/api.php

lib/public/app.php

lib/public/defaults.php

lib/public/groupinterface.php

lib/public/icache.php

lib/public/iconfig.php

lib/public/icontainer.php

lib/public/idbconnection.php

lib/public/ihelper.php

lib/public/il10n.php

lib/public/image.php

lib/public/inavigationmanager.php

lib/public/ipreview.php

lib/public/irequest.php

lib/public/iservercontainer.php

lib/public/isession.php

lib/public/itagmanager.php

lib/public/itags.php

lib/public/iurlgenerator.php

lib/public/iusersession.php