IrreversibleMigration is not raised when a method not supported by reversible migrations is called in the change method of a migration

Allow comparison on model objects - Closes #1858

Removing image/gif from this test.

Removing gif from here because when it got unregister it start failing other places.

Fix test to use Mime::Zip

Fixed issue #1847

Make send_file guess content-type from file extension, if type wasn't supplied (Issue #1847). Update tests & documentation.

default create_with_value to a hash so we can eliminate conditionals, add test surrounding create_with(nil) behavior

Bump ARel to 2.1.3

Asset urls master

  config.action_controller.default_asset_host_protocol

It's best to leave this unset.

When unset the :request protocol is used whenever it can be and
:relative is used in the other situations.

When set to :request then assets hosts will be disabled when there
is no request in scope and will use the request protocol whenever a
request is in scope.

If set to :relative, then a relative protocol is always used except
for stylesheet link tags which must use the :request protocol to
avoid double downloads in IE6&7.

Conflicts:

	actionpack/lib/sprockets/helpers/rails_helper.rb
	actionpack/test/template/sprockets_helper_test.rb

Stylesheet link tags should use the request protocol to avoid duplicate download of stylesheets in IE7 and IE8.

Conflicts:

	actionpack/lib/action_view/helpers/asset_tag_helpers/stylesheet_tag_helpers.rb
	actionpack/lib/sprockets/helpers/rails_helper.rb

Add asset_url helper and refactor the asset paths so that asset hosts can be used during asset precompilation.

Conflicts:

	actionpack/lib/action_view/asset_paths.rb
	actionpack/lib/sprockets/helpers/rails_helper.rb
	actionpack/test/template/sprockets_helper_test.rb

Generating /lib/assets  for assets