php-pear-HTTP_Session can optionally use package "php-pear-DB" (version >= 1.7.6)
php-pear-HTTP_Session can optionally use package "php-pear-MDB" (version >= 1.1.4)
php-pear-HTTP_Session can optionally use package "php-pear-MDB2" (version >= 2.0.1)
