Less stupid Rails translation helper (with blocks for interpolation)

My very first Rails Pull Request!

And meanwhile, you're welcome to copy

I18n testing outfit for Rails 3.2 (also Rails 4.0-stable)

Now put this in config/initializers/i18n_test.rb and spec it!

N.B. Curiously enough, a similar technique is needed for 4.0 as well.

P.S. Tested and working with Rails 4.0-stable, yay!