Add support for:

- distinct function: http://www.mongodb.org/display/DOCS/Aggregation

- modifier functions: http://www.mongodb.org/display/DOCS/Updating

- declaring indexes: http://www.mongodb.org/display/DOCS/Indexes

  User.index :foo

- embeds n, :resources - the work has been started but it's not finished yet

General stuff:

- figure out why DataMapper::Model::Hook and DataMapper::Validate need to be explicitly included on EmbeddedResource

- embeded resources within embedded resources

- figure out how to include the shared adapter spec from dm-core and overwrite Heffalump model so it will work fine

- organize specs in groups (public/semipublic like in dm-core maybe?)

- improve test coverage, especially for embedded resources and handling of custom types

- update README

- clean up and document the code

- write a basic tutorial

And a big one:

 figure out what needs to be improved in dm-core so there won't be a need to override its private API :)