use osrm-datastore for testing, keep osrm-routed runnning

This branch uses osrm-datastore to load data during cucumber testing, resulting in a speed up of more than 3x on cached tests. (First run is about the same, since data must be converted with osmosis).

Before each scenario is run, osrm-datastore is used to load the new into shared memory. osmr-routed is then launched if it's not already running. As cucumber exits, osrm-routed is shutdown.

We might want to add some testing of the good ol' way of loading data directly with osrm-routed, since with the current version of this branch, osrm-routed never load data directly.

I did experience some weird behaviour when trying to launch osrm-routed manually from the command line, and then running osrm-datastore from the cuke scripts, including errors in datastore indicating failure to free data, osrm-routed not returning correct routes, and osrm-routed throwing exception. This should perhaps be investigated. But when launching both routed and datastore from the cuke scripts it seems to work fine.