Add helper for getting a line given a route id

This will be used by Windshaft for displaying indicators on the
map, which is why the reprojection to lat/long is needed.
Fix sbt Scala 2.10.2 artifact downloads

See: http://typesafe.com/blog/what-happened-to-my-travis-ci
Merge pull request #101 from WorldBank-Transport/feature/reproject-line

Add helper for getting a line given a route id