Refactors Ogr::Split to not require having an instance created first
Refactors Ogr::Split to return Shapefile instances

We're pretty much always going to want Shapefiles, and there's no real
downside to using them.
CartoDB importer now imports points

Importer refactored to use WDPA Releases and utilise its ability to get
the geometry tables from a GDB.
Merge pull request #40 from unepwcmc/cartodb-refactor

CartoDB importer can now import points