Populate name column for route relations

[pnorman]

The C transforms used to turn the name tag into a route_name tag on
route relations, for reasons that are not entirely clear. This change
doesn't remove route_name, but does also populate the name column,
eliminating a source of confusion to users.

Fixes #315

[woodpeck]

The C transforms used to turn the name tag into a route_name tag on
route relations, for reasons that are not entirely clear.

The reason for this was that in times past, the openstreetmap.org Mapnik rendering would render the names of anything that had the name column set, so populating the name column on route relations would have forced them all onto the map. This has been fixed years ago though.

[pnorman]

The reason for this was that in times past, the openstreetmap.org Mapnik rendering would render the names of anything that had the name column set

Ah, of course - the fallbacks. That explains why.

I'm still in favour of this change. fallbacks that generically render all name tags have been broken for years. If anyone is rendering all name tags with recent data and a recent osm2pgsql, this will hardly increase how broken their style.