allow config.action_controller.filter_parameter_logging in environment.rb

http://rails.lighthouseapp.com/projects/8994-ruby-on-rails/tickets/537-allow-config-action_controller-filter_parameter_logging-in-environment-rb

There are 2 reason why I think this would be a good change:

1. The filter parameter logging feels more like a configuration option
than code I want cluttering up my application (controller).
2. Different filter parameter logging could be defined based on what
environment is being run by declaring
config.action_controller.filter_parameter_logging in production.rb/
development.rb/test.rb

Thoughts?