Change ActionController::Parameters#require behavior when value is empty
When the value for the required key is empty an ActionController::ParameterMissing is raised which gets caught by ActionController::Base and turned into a 400 Bad Request reply with a message in the body saying the key is missing, which is misleading.

With these changes, ActionController::EmptyParameter will be raised which ActionController::Base will catch and turn into a 400 Bad Request reply with a message in the body saying the key value is empty.
Minor doc fix of ActiveModel::Naming.

- qoute example line's result when it kind of String
- right ("singular_route_key") method in example
Add Rdoc document for Array#forty_two
Merge pull request #12713 from utenmiki/document

Add Rdoc document for Array#forty_two [ci skip]
Warnings removed for ruby trunk

Same as 4d4ff531b8807ee88a3fc46875c7e76f613956fb
Merge pull request #12727 from arunagw/aa-warnings-removed-ruby-trunk

Warnings removed for ruby trunk
Added rubysl-rexml to Rubinius deps.
Remove "circular require considered harmful" error

rails/generators should not load rails/generators/base since the
latter is loading it.
Merge pull request #12732 from razielgn/additional-rbx-dep

Added rubysl-rexml to Rubinius deps.
Passing args for gemfile entry

Fixing build
Merge pull request #12729 from arunagw/build-fixed-ruby193

Can't used named argument in ruby 1.9.3
More Warnings removed for ruby trunk

Same as 4d4ff531b8807ee88a3fc46875c7e76f613956fb
shadowing variable warning removed
Set the destination_root for plugins

Since the plugin generator is relying on the application one, we need to
define the proper root when creating the plugin. The AppBase class is
not setting the destination_root (this is done via the AppGenerator)
Fix some failing tests for Rails::Paths

Since we are not using the File.exists? alias which raises a warning on
current ruby trunk, few stubs are wrong.
Use consistent order of the arguments
:bomb:
Fix typo in method description in Responder class

Fixes a typo in the description for the call class method in Responder.
Merge pull request #12728 from arunagw/aa-warnings-removed-ruby-trunk

More Warnings removed for ruby trunk
Merge pull request #12735 from linstula/fix-typo-in-responder-comment

Fix typo in method description in Responder class