Update for PHP 8 compatibility

[jhenstridge]

I was updating an old project using pear-Auth to work with modern PHP, and these were the changes I needed to make to get things working. In summary:

• Switch to the new constructor syntax with __construct
• Define $storage_driver and $storage_options properties on the Auth class so they aren't dynamic properties.
• Remove use of get_magic_quotes_gpc
• Fix Auth_Container_LDAP.fetchData method signature
• Try to fix cases where $this->session and $_SESSION[$this->_sessionName] get out of sync

For the last one, it seems that calling session_regenerate_id now causes $_SESSION to point at a new array, leaving the $this->session reference pointing into the old array. This was enough to get things working, but there may be a better fix.