Pass assert_dom_equal message arg to underlying assertion

#assert_dom_equal and #assert_dom_not_equal both take a "failure"
message argument, but this argument was not utilized.

[ci skip]

Rails.logger should have level specified by config.log_level. 

update guide to reflect default HMAC SHA1 in MessageVerifier used in SignedCookieStore

Minor optimization and code cleanup in query_methods.rb

Added to 'Security' section in 'Getting Started with Rails' guide, including reference to 'Ruby on Rails Security Guide'.

Fix active_record_validations.md document, `:save` for `on:` validation helper was never available

According to the guide, ":save" value for the "on:" validation helper
was available like below

    validates :name, presence: true, on: :save

but this was never available according to the implementation of the
valid? method, which is below

    # Runs all the validations within the specified context. Returns
+true+ if
    # no errors are found, +false+ otherwise.
    #
    # If the argument is +false+ (default is +nil+), the context is set
to <tt>:create</tt> if
    # <tt>new_record?</tt> is +true+, and to <tt>:update</tt> if it is
not.
    #
    # Validations with no <tt>:on</tt> option will run no matter the
context. Validations with
    # some <tt>:on</tt> option will only run in the specified context.
    def valid?(context = nil)
      context ||= (new_record? ? :create : :update)
      output = super(context)
      errors.empty? && output
    end

So the documentation was always wrong since the PR proposed by
@neerajdotname  ( #10287 ) was rejected.

We need to call `in_time_zone` to test that it isn't modifying the receiver
but since the variable isn't used it raises a warning so add an assertion
to make Ruby think it's being used.

The section was clearly wrong and was just an example about how to use ActiveSupport helpers in Rack/Sinatra

[ci skip]

[ci skip]

Add note that you must be in the rails app when starting the server

i18n guide update: corrected reference to activerecord to instead reference activemodel

This is a response to issue #11731 and is a common mistake for people
newer to rails that try forget to cd into the new rails app after
running rails new.

Removed an unnecessary loop - it kills performance on large texts.

[Fixes #11734]Correct Association Basics Guide on has_and_belongs_to_many

Changing the def self.table_name to self.table_name in the column_name.r...

used flat_map instead of map.flatten in /guides/rails_guides/helpers.rb

javascript_include_tag "extname" option for use by asset_path

fix for postgresql failing test in local

use flat_map

[JRuby] Avoid calling define_method with non-english chars in InflectorTest

Done the following changes:
 1. Replace uniq call in example with autosave as uniq is not supported
 on has_and_belongs_to_many
 2. Add :readonly option to list of supported call as per
 [EdgeApi](http://edgeapi.rubyonrails.org/classes/ActiveRecord/Associations/ClassMethods.html#method-i-has_and_belongs_to_many)

ActionView::Helpers.asset_path is where the logic for
javascript_include_tag resides.  It takes an extname option for
specifying the extension or false to not append it.  This exposes that
option to javascript_include_tag.

Without the option files that didn't end with ".js" would get the
extension appended to them.  This broke JST templates and other file
types that should be interpreted as JavaScript but who's file extension
isn't ".js"

Using URI.parser.unescape

Fixes warning

warning: URI.unescape is obsolete

When we call define_method with non-english chars like ¿por qué? it
errors out on JRuby as of 1.7.4 & would leave out the following error

invalid byte sequence in US-ASCII

To work around this issue, I have switched to define_test method call
define method with fixed string & the index of the hash. the index was
added because otherwise, ruby will raise method redefined warning.

As far as I can see there are no side-effect of this change for
other implementations. For readbility I have added a message to
asssert_equal informing for which word/phase the test has passed.

Before this Change:
JRuby:
Tests terminated suddenly with an error. no reported of Failues
or errors
MRI:
All Green.

After this Change,
JRuby:
the `ActiveSupport` TestsSuite gracefully fails with report at the end which test failed & why.
MRI:
All Green(no change)

Updated the guide to say that the localisation file for validation messages is in activemodel, not activerecord

This fixes railties tests in JRuby but break it in MRI
This reverts commit fea99276.

Isolate railties Generators Tests