Distinct: add basic distinct to the query DSL (+ add to PG adapter)
Distinct: refactor group_by/distinct into BuilderUtil
Distinct: factor out common code for distinct/group_by in normalizer
Distinct: rework validator to ensure group_by leftmost express match the distinct expr
Distinct: validate distinct on order_by not on group_by
Distinct: rename escape_expr in escape_fields_and_var + Enum.first => List.first
Distinct: proposal for the documentation of 'distinct'
Distinct: add a 's' to the function name, to be consistent
Distinct: add a test for distinct without order_by
Distinct: add some metadata to the error raised by the validator
Update to elixir master
Add convenience conversion functions to Ecto.DateTime
Merge pull request #151 from Enders/distinct

Distinct: add basic distinct to the query DSL (+ add to PG adapter)
Order of distinct fields should not matter
Remove Ecto.Query.from/1 and Ecto.Query.__using__/1

Since we added the queryable protocol, there is no need
to create a query by doing `from(p in Post)`, we can simply
pass `Post` as argument.
Fix the docs of Ecto.Model.Validations
Merge pull request #164 from mururu/fix-doc

Fix the docs of Ecto.Model.Validations
Range fix
Merge branch 'master' of https://github.com/elixir-lang/ecto into dev
fix some tests to new ecto master