ITS#10193 Asyncmeta starts more than one timeout loop per database and slaptest crashes

There were missing checks for tool mode, so slaptest crashed trying to schedule a task. Also, the timeout loop should not be started when adding a target via cn=config, unless the server is already up and running, since we already do this on db_open. These are not the only issues with the cn=config code, but I need to test some more and will open a separate ticket for those.