Should All function be able to take queries?

Should we be able to pass a query to the `all` function?

Currently `all` gets all the the distinct `:entry_id`s from the database, orders the results and removes any values where deleted is true.

This works well but does not allow us to do any further database queries.

For example, if you wanted to retrieve a list of all users from a user table who were under 50. With `Ecto.Repo` you would be able to pass in a query that looks something like...
```elixir
query = from(u in user, where: u.age < 50)
Repo.all(query)
```

The database does all the logic and returns only the data you need.

With the current `all` in `alog` we would need to retrieve all users and then filter them ourselves in app.

@danwhy @nelsonic any thoughts/suggestions on how we can extent the `all` function to all users to pass in any query but still keep/use the current query?