Core/Commands: Enable SQL query logging by config and command )patch by leak)

Closes issue 4853.

--HG--
branch : trunk

sql/updates/10470_world_command.sql

@@ -0,0 +1,3 @@
+DELETE FROM `command` WHERE `name` LIKE 'server togglequerylog';
+INSERT INTO `command` (`name`,`security`,`help`) VALUES
+('server togglequerylog',4,'Toggle SQL driver query logging.');