fix rake db:migrate when used with ENV['DATABASE_URL']

make connection_url_to_hash a class method

This als prevents loading database.yml if it doesn't exist
but DATABASE_URL does

Remove XML Parser from ActionDispatch

If you want an ability to parse XML parameters, please install
`actionpack-xml_parser` gem.

descriptive error message when AR adapter was not found. Closes #7313

Fix time_zone_options_for_select to not mutate TimeZones array

Improve upgrading guide with ActionDispatch::BestStandardsSupport remova...

Previous implementation of time_zone_options_for_select did not dup the
ActiveSupport::TimeZone.all array.  When :priority_zones were provided
the method would reject! the zones from the memoized TimeZones array
thus affecting future requests to the server.  Essentially whatever
zones were specified as :priority_zones would show up for the first
request but then disappear from the time zone options on future
requests.

added more accurate test for add_on_empty

with the current tests, if delete the assignment of is_empty in add_on_empty method
the tests not fail. With this test, if we delete is_empty, the test fails

delete duplicated tests in AR base_test.rb

Raising an error when query methods have blank arguments.

These are duplicated with the tests which are in relations_test.rb

Closes #9302

Require ActiveSupport dependencies in ActionDispatch::Http::URL

Allows us to use url_for and friends in isolation.

Most application developers shouldn't be adding paths to
`config.autoload_paths` as it won't be eagerly loaded so
remove it from the generated config/application.rb file.

If a developer does want to autoload from paths outside of the app
directory then they should add the path to `config.eager_load_paths`
as these paths are also autoloaded as well.

Whilst autoloading is known to be not threadsafe, leaving it in place
is a softer solution than failing hard when an application is deployed.

Many older applications will have paths added to `autoload_paths` and
ideally these should be eagerly loaded to be threadsafe. However one
of these paths is quite often lib which could lead to unintended
consequences due to the 'junk drawer' nature of this directory.

Developers should refrain from adding paths to `autoload_paths` or
`eager_load_paths` and use custom folders inside app for code that
needs to be eagerly loaded and use `require` or `require_dependency`
to explicitly load code from other locations.

Because of the possibility of lib being unintentionally eager loaded
it's been agreed that we'll leave autoload paths and eager load paths
separate for Rails 4.0.

This reverts commit 0757b338.

Conflicts:
	railties/CHANGELOG.md

Somehow I missed this method, which was then throwing an error
when viewing routes as HTML.

Make @rubys happy: ✔

Thanks @sikachu. 😅

Thanks @sikachu. ❤

Print message on stderr when no routes are defined.