mongodb/mongo-ruby-driver — pull request #232 by estolfo (2013-07-25 00:04:23+00:00)
Title: RUBY-592 Initial Cursor implementation and specs

## Initial Cursor implementation
This pull request implements the basic functionality of a Cursor. It is a client-side representation of an iterator over a query result set on the server.

A Cursor is created in a terminator method of a Scope. For example,

collection.find.limit(5).to_a

will create a Cursor and call #to_a on the Cursor.

## @todo tags

### Interfaces
The interface for selecting a node and sending a message to it is not clearly defined right now, nor is the interface to client. The @todo tags mark places that need to be updated as the interfaces become defined.

### Exceptions
The Exception hierarchy is still undefined so an Exception is used in place of a more precise and meaningful class.

### Less significant features to add later
For the time being, the follow cursor features have been left out and will be added later:
* exhaust
* explain
* no_cursor_timeout option

#### Note that yard documentaiton will be added later, after intial code review