Rename set_x methods to x=
Add column helper methods for other geo types
Cleanup BasicTest

* Make #populate_ar_class private
* Rename variables
* Why did attribute values have a #factory method?
Add PostGISAdapter::SchemaCreation
[WIP] Add #add_spatial_column to SchemaStatements
Rename method to #spatial_column_options

* Rename constant to SPATIAL_COLUMN_OPTIONS
Update index handling

* Remove #add_index override
* Override #add_index_options