Don't loop twice over svg rows
Order by dimension so it's possible to stream the rows as they come
Merge branch 'master' into formats-svg-topojson-improvements

Conflicts:
	NEWS.md
Improve topojson output by streaming json
Fallback to nextTick for node v0.8, resolves #182
Merge pull request #186 from CartoDB/formats-svg-topojson-improvements

Formats svg/topojson improvements