dm-active_model

This plugin makes datamapper compliant with active_model conventions and thus compatible with rails3.

Note on Patches/Pull Requests

Fork the project.
Make your feature addition or bug fix.
Add tests for it. This is important so I don‘t break it in a future version unintentionally.
Commit, do not mess with rakefile, version, or history. (if you want to have your own version, that is fine but
```
 bump version in a commit by itself I can ignore when I pull)
```
Send me a pull request. Bonus points for topic branches.