Added a 'whiny nil' that's aim to ensure that when users pass nil to methods where that isn't appropriate, instead of NoMethodError? and the name of some method used by the framework users will see a message explaining what type of object was expected. Only active in test and development environments by default #1209 [Michael Koziarski]

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@1454 5ecf4fe2-1ee6-0310-87b1-e25e094e27de