Documenting configuration options

Currently a whole slew of Rails configuration options aren't being included in the RDoc generated documentation (basically most of ActiveRecord::Base, ActionController::Base, etc). This is due to RDoc not picking up comments on cattr_accessor's.

I've looked at some of the options for solving it here:
http://dev.rubyonrails.org/ticket/10424

Run the attachment on the ticket through rdoc to see what I mean:
http://dev.rubyonrails.org/attachment/ticket/10424/documenting_cattr_accessors.rb?format=raw

-- tim