version 0.9.3
- Fixed example for 'from_validator' in documentation.
- Better checking of formula specification of collapsing scheme.
- Improvements in documentation (thanks to the JSS editorial 
  team for pointing them out).

vesion 0.9.0
- Package now supports complex objects as aggregation output
- Internal: complete code reorganization

version 0.8.1
- Added URL to description
- Fixed typo in DESCRIPTION (thanks to CRAN team)

version 0.8.0
- First CRAN release attempt