get csrf_meta_tag back to the generated layout in deference to existing printed material, chomp also the generated HTML to be faithful to the output before the refactor

This setting was existed since Rails 2.3.x, and seems like it have been left out when we rewriting the documentation.

Signed-off-by: NMikel Lindsaar <raasdnil@gmail.com>

  http://rdoc.rubyforge.org/RDoc/Parser/Ruby.html

removes /i from the TRUSTED_PROXIES regexp, adds /x and comments for readability, adds a pointer to a Wikipedia section that documents the matched IPs

Useful for cases such as warden, where a block configuration is taken.

    class SomeController < ApplicationController
      use RailsWarden::Manager do |manager|
        manager.default_strategies :facebook_oauth
        manager.failure_app = SomeController.action(:authorize)
      end
    end

Signed-off-by: NMikel Lindsaar <raasdnil@gmail.com>

Signed-off-by: NMikel Lindsaar <raasdnil@gmail.com>

Partial revert of commit #7fae0aa4 removing action_dispatch.prepare_dispatcher per commit #48bf667a

See line note:
http://github.com/rails/rails/commit/7fae0aa4ac116bcbf522a9a4f19972c653d366fa#commitcomment-145148

revises implementation and documentation of csrf_meta_tags, and aliases csrf_meta_tag to it for backwards compatibilty

[#5610 state:committed]
Signed-off-by: NJeremy Kemper <jeremy@bitsweat.net>

Signed-off-by: NMikel Lindsaar <raasdnil@gmail.com>

added a test for relation which checks intersection between a relation and an array works in both directions
Signed-off-by: NMikel Lindsaar <raasdnil@gmail.com>

Cheaper attribute reads and respond_to?. Add underscore-prefixed method aliased to the attribute name so it can be overridden but still called internally.