Remove AC::RenderError class second declaration

Fix deleting from a HABTM join table upon destroying an object of a model with optimistic locking enabled.

Merge pull request #5668 from plashchynski/validate_attribute_name_in_class_and_module_attribute_accessors

validate attribute names in class and module attribute accessors

Nested attribute setters can be overridden.

Typecast 'id' attribute in read_attribute when using custom pks

post.slice(:title, :content) # => { title: "Hello", content: "World" }

Spring cleaning in Rails::Paths

Add config option to turn off prefixing partial path with controller namespace

Changing active model dirty module helper method to more appropriate met...

Missed commits from 3-2-stable

config.action_view.prefix_partial_path_with_controller_namespace

This allows you to choose to render @post using
/posts/_post.erb instead of /admin/posts/_post.erb
inside Admin::PostsController.

Overriding implementation can call super.

Possibly clearer way of getting rid of ` and "

Remove code duplication in InclusionValidator and ExclusionValidator.

Orginal code by @jamescook

Closes #1352

[Rafael Mendonça França + James Cook]

Closes #5632

clarification to prevent confusing newbies; Passenger/Unicorn are app servers, Apache/Nginx are the web servers along with thin a la Heroku etc.