Rename the "sql" directive to "db". Rename the "log" directive to
"log fs".
In the future, we'll maybe support more databases and more message
stores. Make it so it's easy to integrate these new festures to the
config file format.
git-svn-id: file:///srv/svn/repo/suika/trunk@507 f0ae65fe-ee39-954e-97ec-027ff2717ef4