Use ActionView::Base.cache_template_loading to avoid caching

I just had another look and it seems like #56 was much too fast yesterday. It actually does not work, since the cache attribute is not writable anymore in Rails 4. It in fact causes an exception, which I did not see since it's caught somewhere.

Nevertheless, https://github.com/rails/rails/pull/10791 is available since 4.0.1, so here is my try to make use of it. Could you please have a look at it and comment on this change, @eprothro and @Mik-die.

As I said, the BlackHole implementation causes issues for me, so it's definitely not ideal.