Add new vector isochrone builder (grid sampling).

Handle disjoint sets and holes.
Allow for multiple isochrones to be computed on the same request.
Based on current analyst SamplingFactory.
Add new accumulative grid sampling isochrone.
Greatly optimize isochrone ring generation.

Remove the h/v sets and use a processQ.
Optimize isochrone sampling with a SparseMatrix.

This divide by 3/4 the sampling time.
Remove XYindex with it's slow translated() method.
Remove all Maps from the implementation.
Add fastDistance/Length with cached cos(lat).
Optimize isochrone by caching cos(lat).

Correct distance computation (d is not homogeneous coordinates).
Isochrone: simplify sample closing to 1 stage.
Isochrone: provide defaults for neighbors if avail.
Isochrone: various refactoring and renaming.

- Add routerId parameter to the request.
- Add algorithm parameter to select between implementations.
- Rename various classes.
- Extract IsochroneSPTRenderer interface.
- Rename web-service from /iso2 to /isochrone.
Isochrone: remove too small rings.
Make SparseMatrix implement Iterable.
Iterating on empty SparseMatrix unit test.
Isochrone: Add SPTWalker to visit SPT geometry.
Isochrone: Make use of the SPTWalker in rendering.
Correct wrong comment.
Isochrone: use generated origin edges in SPT walk.
Isochrone: Use generics for Z instead of double[].
Vectorizer: extract grid sample mgt to own class.
Vectorizer: delegate coordinate mgt to sample grid.
Vectorizer: Remove generics for user data.