MongoDB command

[michalmuskala]

We probably need to support commands for database management. Currently there's Mongo.Ecto.command/2 to send direct command to the database. I implemented also functions that use this for particular commands: create_collection, list_collections and drop_collection for managing collections (as I needed those for the truncate function).
There are a lot of commands, and some should have a specialized function, but majority shouldn't - I'm not sure where to draw the line.

The list of all the commands is here: http://docs.mongodb.org/manual/reference/command/

I think we should definitely have specialized functions for collections and indexes, about others I have no idea.

[josevalim]

I would recommend at least documenting those. Mongo.Ecto should @doc false all callback definitions and explicitly document all extra functions that are meant to be used directly by developers. :)

Regarding exposing the commands, it seems fine to allow the user to pass anything, which we just pass to mongo. We can link to the mongo reference too.

[michalmuskala]

We have a command function. I'm closing this.