Remove ogr2ogr dependency

[gravitystorm]

Given that we only need it for one minor task, we should remove the ogr2ogr dependency from the setup. It's not too bad on linux systems (yay package management) but it's an unnecessary hurdle elsewhere.

If we can't get the NE shapefile fixed upstream, then lets host a fixed version of the file somewhere and grab it from there instead.

[pnorman]

This was fixed in mapnik/mapnik#1605 (comment) but we'd have to bump the required version to 2.2, which hasn't yet been released.

This would also impact #45 but because ogr2ogr is warning about encodings we should check that the rendered result gets it right before dropping ogr2ogr.

Hosting a fixed version would of course render the issue moot

[pnorman]

If hosting a fixed version we should strip out unnecessary shapefile fields to save space. Have we contacted NE to ask about getting them to fix the issues?

[springmeyer]

@pnorman, natural earth maintainer was hired by apple, so "we" are all natural earth maintainers now.

[pnorman]

Created a NaturalEarth Correction ticket (UA3125RX4Z) as that seems to be the only way on their site. If we get no response, I guess we'll have to look at hosting a fixed version on planet.osm.org or somewhere?

[tomhughes]

@pnorman if mapnik 2.2 is fixed does that mean we can skip the ogr2ogr step on the production servers which are using 2.2?

[pnorman]

My reading of git is that mapnik/mapnik@913e1d0 is in 2.2.0 but I'm not 100% confident.

Also I haven't tested.

So almost certainly, but a slim chance of a problem.

[tomhughes]

That commit is in 2.2.0 yes.

[pnorman]

If we can't get the NE shapefile fixed upstream, then lets host a fixed version of the file somewhere and grab it from there instead.

Well, since this seems to not be an option, how about hosting a fixed one on planet.osm.org? I know it's not ideal, but neither is requiring ogr2ogr or mapnik 2.2.

On the other hand, if andy is planning on introducing features that require mapnik 2.2 then we can drop ogr2ogr when the minimum mapnik version is upgraded

[pnorman]

One other option is to use mapnik-config -v to identify if we have mapnik 2.2.0 or later and if so, skip ogr2ogr.