implemented basic pdo functionality to db layer
fixed some minor typos to try to get pdo layer working.  removed some mysql dependencies
finally got pdo-db working (at a very basic level, with bugs
resolved issues 172 and 173 - item tags are now fetched correctly, and unread items correctly rendered
temporary so can switch branches
resolved issue 178, nav links displayed twice.  Easy fix, just removed the second place where it was displayed.  not sure how this happened, but whatever
resolved issues 177 and 175, stopped session id being regened by fixing session database loader.  CSRF system works again, and we can update the prefs
database connection string no longer hard-coded for mysql
used the new prepare_query_log function in fof_db_get_items, with a loop.  Might be slow, need to check performance.  If too slow, need to generate in (?,?,?...) for query, etc.  Current method has nice code, so I'd like to keep it as is
resolved issue 180 (intermittent authentication failure for persistent logon), performed significant work on issue 19 (use pdo as db layer
removed deprectaed db functions in fof-prefs.php
resolved issue 181, removed dead schema upgrade code, upgraded all database queries from outside fof-db.php to the new pdo functions
resolved issues 184 and 170 - implemented cross platform abstraction arount PDO::lastInsertId, used transactions to prevent potential race condition
finished implementing new pdo_db database access functions (ie completed issue 19).  Still need to remove old db access functions
removed the fof_prepare_query_log function, will focus on performance issues later
resolved issue 171, don't need to reconnect to db on session write, prevented connection being garbage collected away