1.00

- Port to S-plus
1.1
- some cleanups for citation() and codetools bugs
1.3 
- minor typo in example
1.5
- Splus porting
2.0
- Refactoring to use generics and assignment methods, performance improvements
2.1
- Bugfix in summary.urn
- R cmd check under 2.10.1 fixes
- Standarize S3 methods
2.2
- Fix typos