Patch review requested part deux

Until a solid review process is decided, here goes:

#8117 - bug fix for calculations not using :foreign_key for grouped associations

#6107 - don't pluralize class names if ActiveRecord::Base.pluralize_table_names set to false

#8153 - fix a tiny copy and paste job for naming a test method

#8717 - reference ActiveResource in railties Rakefile and release.rb

Regards, kamal