This function writes all of the database to standard output.

• Passes execution off to $smcFunc['db_get_backup'] if the current db is flat-file (eg SQLite)
• Calls $smcFunc['db_list_tables'] to get the table info
• If we're backing up data as well, calls $smcFunc['db_table_sql'] to get the SQL for the table data
• Used to create the sql (or sql.gz) file