change some fixed config variables to be forced_default. Three types of variables: 1. default(first, set in memory with the value in seek configuration files; second, resettable in DB by admins with 'server admin' ) 2. forced_default(only set in memory with values in seek configuration files) 3. fixed(set in DB with the value in seek configuration files). The values load order is: it reads DB first, then in memory if not found.