Add headway calculations for mode/route

Results are in units of hours per vehicle
Refactoring based on PR feedback
Merge pull request #99 from WorldBank-Transport/feature/add-headway-calculations

Add headway calculations for mode/route
Add path prefix parameter to setup_db script

This allows the script to be run from within scala unit tests.
This is needed, because the JVM doesn't allow changing directories
while running commands (in order to support multiple OS/file systems).
Store data as lat/lng, but read from DB as UTM
Refactor parts of GT service into companion object

For easier unit testing
Add trait for setting up fresh test databases
Integrate test database into scala tests
Fix typo
Merge pull request #100 from WorldBank-Transport/feature/scala-test-db

Create test database for scala tests
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
Add the_geom 4326 cache column to Indicators model
Update Windshaft to use Indicator API

Windshaft now displays Indicators, rather than test data
URL is:
/tiles/:dbname/:version/:type/:sample_period/:aggregation
Calculate indicator geometry in scala for route aggregations

Geom for an indicator should be calculated with the indicators
themselves, and POSTed to the Indicator API endpoint.

Geom can be an empty string if not relevant.

TODO: Calculate indicator geom for mode aggregations
Update map-controller for new Windshaft API

TODO: Dynamically select indicator URL and refresh layers
based one UI selection
Add support for dynamic indicator selection in UI
Allow selection of all available route indicators
Update to match PR #101