moved geojson support into core module
renaming root and core pom
tweaking version / revision output
disabling shade, and removing geojson dependency
data api refactoring

- VectorData -> VectorDataset
- TileSet -> TileDataset
- Removed Registry.Item
- Simplified DataRef
not throwing exception when driver declares no keys
outputting json from cli commands
factored out registry create into separate method
fixing some formatting and comma issues
added optional argument to driver command for specific driver
using workspace/dataset as type value
added carto driver
added JSONRegistry
Refactored feature classes