Get ActionPack's test running on bundled gems. This should make running tests on new machines, as well as CI, work well.

Activate rack-test gem before it's required. This shouldn't be necessary, but should fix the build for now

Cleanup route reloading in tests. Prefer with_routing over using ActionController::Routing::Routes directly

Replace _action_view with view_context to reflect that it is public and that it does not need to be an ActionView instance

  - Define to_model on AR
  - Define to_model on ActiveModel::APICompliant
  - Update test fixtures to be API Compliant
  - Start using to_model in AP

Got new base to pass controller/base_test.rb, implemented method_missing action semantics in compatibility mode, and fixed a few action_missing bugs.

Signed-off-by: NJoshua Peek <josh@joshpeek.com>

  # Default locale
  app/views/messages/index.html.erb

  # I18n.locale is set to :da (Danish)
  app/views/messages/index.da.html.erb

Revert "Super lazy load view paths in development mode (no indexing or caching at all). Switch layout finders to use view path api to take advantage of cache." as it killed dev mode reloading.

This reverts commit 4d910b03.

Reinstate "Super lazy load view paths in development mode (no indexing or caching at all). Switch layout finders to use view path api to take advantage of cache." as it killed dev mode reloading."