Add appdb/tables/create_tables script to run the sql necessary to create and

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.

tables/user_list.sql

@@ -1,3 +1,6 @@
+use apidb;
+
+drop table if exists user_list;
 
 create table user_list (
 	stamp           timestamp not null,