Added use_silence parameter to ActiveRecord::Base.benchmark that can be passed false to include all logging statements during the benchmark block. Added ActionController::Base.benchmark and ActionController::Base.silence to allow for easy benchmarking and turning off the log

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@2140 5ecf4fe2-1ee6-0310-87b1-e25e094e27de