add user notice support to pages when not logged in
add PBKDF2 password hashing library from
https://crackstation.net/hashing-security.htm#phpsourcecode
added support for user logins authed against a DB (mysql and postgres
tested so far). the config object is passed in but not used yet, the
settings are still hard coded in the class
include the newly added PBKDF2 lib
changes to support the new db auth session code. don't do a redirect
when there is no active session, and activate the DB auth session code
(this needs to move upstream so it can be easily site specific)