seancribbs/ripple — pull request #245 by joedevivo (2011-11-21 20:07:22+00:00)
Title: Doc indexes

Added index method to Indexes::ClassMethods

Example:
```ruby
class User
include Ripple::Document

property :firstname, String
property :lastname, String

index :fullname, String do
"#{self.firstname} #{self.lastname}"
end
end
```
Creates and persists a secondary index "fullname_bin" with the value as evaluated by the block.