Thread:Support/ago ("$1 ago") cannot work

In r97962, the message has been added, noting ''Introduce an 'ago' message for '$1 ago'. Not currently used in core, but I want to use it in an extension and it seemed stupid not to have such a thing in core.'' But this cannot use the basic messages (e.g. ) in flective languages. E.g. in Czech, something takes “10 sekund”, but something happened “před 10 sekundami”, because the “před $1” corresponding to “$1 ago” uses the instrumental case.

Either drop the ago message until somebody needs it, or introduce specialized submessages for it.