Make /rails/info/properties work again. Also, the mocked up tests were passing so we added a test that actually tested this functionality.

Isolation tests intentionally avoid loading any state (because they're often testing things that have their own load path semantics that should not be polluted), so rack/test is not yet  on the load path. Moving require "rack/test" into the setup means and after boot_rails means that it'll be required after the laod path has been altered to add in the Rails vendor/gems

According to RFC 4627, only the following Unicode code points are
allowed unescaped in JSON:

  unescaped = %x20-21 / %x23-5B / %x5D-10FFFF

However, ActiveSupport::JSON did not escape the range %x00-1f.  This caused
parse errors when trying to decode the resulting output.

[#3345 state:committed]
Signed-off-by: NJeremy Kemper <jeremy@bitsweat.net>

Fixes "Rack-mount boot time is slow as shit" [#3567 state:resolved]

Signed-off-by: NYehuda Katz <wycats@Yehuda-Katz.local>

Conflicts:
	railties/test/initializer/initialize_i18n_test.rb
	railties/test/initializer/path_test.rb

Fix the documentation for root :to. It should use a fully qualified controller#action syntax (Closes #3606)

Fix ActionMailer. The fact that ActionMailer::Base does not inherit from AbstractController::Base is either a bug or we need to re-evaluate the requirements of the mixins.