ported checkLoggedIn and checkAdmin

apps/admin_migrate/settings.php

apps/bookmarks/addBm.php

apps/bookmarks/index.php

apps/calendar/export.php

apps/calendar/index.php

apps/contacts/export.php

apps/contacts/index.php

apps/contacts/photo.php

apps/contacts/thumbnail.php

apps/external/ajax/setsites.php

apps/external/index.php

apps/external/settings.php

apps/files/admin.php

apps/files/ajax/download.php

apps/files/download.php

apps/files/index.php

apps/files/settings.php

apps/files_sharing/list.php

apps/files_sharing/settings.php

apps/files_versions/history.php