Default rules files and river names

[andreadecorte]

River names are currently not showed. I tried to add just a draw:text but the problem is that name appears even for lower zoom levels, so it's a bit annoying. Any idea how can we show them only with zoom >= 13 as in Mapnik?

[quelbs]

Names for rivers in zoom >= 13 is added with e0a0779 for default ruleset.