Fix CookieStore middleware inheritance hierarchy s.t. it inherits from Rack::Session::Abstract::ID rather than Rack::Session::Cookie.
Revert cb3181e - no longer required.
Merge pull request #8824 from mjtko/fix/cookie-store-inheritance

Modify CookieStore middleware inheritance to avoid subclassing Rack::Session::Cookie [Fix for #7372]
Bring back "database already exists" messages when running rake tasks

When running tasks such "rake db:setup", instead of showing messages
like "db_development already exists", it was showing a big stack trace
and a message "Couldn't create database for ..." with the configuration
options, a very confusing message with a big trace.

This brings back the functionality present in 3-2, showing the same
message.