Add new unsorted shape point DAO

[laurentg]

Same comment as for stop times: the current "packed" DAO implementation work best with sorted shape points. The alternative implementation rely on the small shape points which can be better optimized by using an intermediary implementation (packing, but with allowing random order).

See issue #51.

[laurentg]

MBTA

---[ Packing sorted shape points crude memory stats ]---
       What       |    Count   | Total (kB) | Per item  
------------------+------------+------------+-----------
     Shape points |     323150 |       1580 |       5.01
           Shapes |        952 |          7 |    1700.25
------------------+------------+------------+-----------

--[ Packing unsorted shape points crude memory stats ]--
       What       |    Count   | Total (kB) | Per item  
------------------+------------+------------+-----------
     Shape points |     323150 |       3816 |      12.09
           Shapes |        952 |         29 |    4105.32
------------------+------------+------------+-----------