setup appdb tables. Add app_category.sql and session_list.sql from Jeremy,
without these the database wasn't handling logins correctly and had no
categories. README now has some instructions on how to setup a local appdb.
Modified config.php.sample to point to apidb to match what is in the sql in
appdb/tables. Sql for table creation to use "if exists" to prevent data
base errors on trying to drop tables that don't exist.
