This allows code in lib, model etc to not worry about GeoAlchemy
versions. This assume the correct library installed, as the check has
been done when starting up.
Tests are passing, apart from a couple which didn't work before:
* test_functional.py -> functional/test_package.py (3 failures in 4)
* functional/test_dataset_map.py (1 fail in 1)
There may be some code errors still untested.
Renamed Validator -> Validators to make more sense.