Add ActiveRecord::attribute_names to retrieve a list of attribute names. This method will also return an empty array on an abstract class or a model that the table doesn't exists.

Do not try to call `column_names` on the abstract class.

Normally the table for abstract class won't be existed, so we should not trying to call `#column_names` on it.

 * It is not necessary to subtract 'id' from the list of copied attributes because record and mem_record are equal, so therefore their id attributes are also equal (so there is no harm in copying it, and this reduces the complexity of the code)
 * It is not necessary to intersect the attribute names, since record and mem_record are equal, so they have the same id and class, so they have the same columns in the database. If record has non-column attributes then it seems reasonable to also copy them onto mem_record (though I am not sure what situation this would ever happen in)

CollectionAssociation#merge_target_lists should write to the underlying attributes when copying, rather than using the assignment method

ActiveRecord::LogSubscriber.runtime should be reset at the start of each request

Previously the runtime was reset implicitly when #cleanup_view_runtime was called at the end of most requests. However, this doesn't happen when the request redirects, or send_file is called.  Consequently, the ActiveRecord runtime recorded in the logs included the time taken for both the current request and the previous redirect.  Explicitly resetting at the start of each request ensures that this can't happen, no matter what occurs previously.

Conflicts:
	actionpack/lib/action_view/helpers/date_helper.rb
	railties/lib/rails/generators/rails/app/templates/config/initializers/wrap_parameters.rb.tt

Fixed failing tests for namespaced_generators_test. in 1.9.2

[GUIDES] Changed the `LANGUAGE` variable to `GUIDES_LANGUAGE` to minimize conflicts with regular environment variables (eg. in Ubuntu)

asking the user whether he is "offline" rather than "online" seems more natural as reaction to a potential missing network connection

typo

Remove pointless rescue (it doesn't happen anywhere in the tests, and I can't see a way that it would happen ever)

Update Mailer generator to use 1.9 styled hash when run on Ruby 1.9

As always, you can run `--old-style-hash` to override that.

Use new hash syntax in wrap_parameters initializer under Ruby 1.9

rack_mount upgrade to new version 0.8.0

Note that it currently links to http://edgeapi.rubyonrails.org because it's Rails 3.1 feature.