comma-csv/comma — pull request #72 by eitoball (2013-08-17 01:14:17+00:00)
Title: Yield model instance in __static_column__ keyword's block

This gives `__static_column__` keyword more flexibility. For example, example in #41 can be written like:
```ruby
comma do
name
description

publisher :name

publisher.custom_data.each do |header|
__custom_column__ header do |o| o.custom_values[header] end
end
end
```
I think that this is cleaner.