Implements streaming CSVs.

Allows unlimited downloads of CSV data using ActiveRecord batch APIs and ActionController response streaming.

Works on Rails 3.2+
Actually pass the options to generate_line.
Make the meat and potatoes of streaming protected.
Add no-cache header to streaming CSV responses.
Disable downstream response buffering of stream
Add header_action method for panels
Use Capybara to better test panel rendering
Add humanize_name option to CSVBuilder#column to control humanization of column name.
Add humanize_name option to CSVBuilder too and pass it to its columns.

This allows a much DRYer code if you have many column namess you don't
want to be humanized. As a bonus, any other transitive option like this
one can be added easily in the future.
Add a JS hook for has_many_remove:after
use the `permit_params` DSL everywhere
#3147: raise error for those still using `default_actions`
fix `permit_params` for renamed resources

specifically, this fixes the tests for AA::Comment
:nail_care:
remove Rails 3.1 ActiveModel::Name compatibility layer
Use latest cucumber-rails release
give optional deps in Gemfile their own section
don't specify a version for Devise in the Gemfile
#3005 appears to be resolved!

…though we have to specify a version for sass-rails (#3093)
update sass-rails requirement to work with Rails 3

#3005, #3093