Merge pull request #13012 from harrigan/master

Helper should be a module in Rails guides [ci skip]
sync example and documentation for strong_parameters hash whitelisting.

[ci skip]

This is a follow up to #12609 and integrates #12158.

Thanks @aspiers.
Closes #12158.

Conflicts:
	guides/source/action_controller_overview.md
Remove single trailing ')' bracket
Merge pull request #13057 from bricejlin/patch-1

Remove single trailing ')' bracket [ci skip]
Fix bug when validating the uniqueness of an aliased attribute.
Merge pull request #13061 from laurocaetano/fix-uniqueness-validation-for-aliased-attribute

Fix bug when validating the uniqueness of an aliased attribute.
Merge pull request #13018 from heruku/scoping_fix

changed update counter to act on unscoped model
Conflicts:
	activerecord/CHANGELOG.md
	activerecord/test/cases/associations/has_many_associations_test.rb
Merge pull request #13070 from kuldeepaggarwal/documentation-updation

[ci skip] used new syntax for scopes
Merge pull request #13071 from kuldeepaggarwal/documentation-updation

[ci skip]removed obsolete information about `options` parameter in create method
Merge pull request #13067 from sagarjunnarkar/getting_started

Link for "New Post" is added in Getting Started guide [ci skip]
Merge pull request #13104 from christophemaximin/fix_robots_txt_link

Fix URL to robots.txt documentation [ci skip]
Merge pull request #13107 from chancancode/has_one_counter_cache_should_raise

Raise `ArgumentError` when `has_one` is used with `counter_cache`
Conflicts:
	activerecord/CHANGELOG.md
	activerecord/lib/active_record/associations/builder/belongs_to.rb
	activerecord/lib/active_record/associations/builder/singular_association.rb
Merge pull request #13055 from dmitriy-kiriyenko/fix-segmentation-fault-it-ruby-2.0.0-p353

Fix segmentation fault in Ruby 2.0.0-p353.
Removed redundant field name in the guide

Fixes: #13108
[ci skip]
Honor to RAILS_GROUPS env variable while loading gems with Bundler
config.assets.enabled isn't used anymore to disable Rails asset pipeline
Changelog entries for changes in config/application.rb template
Merge pull request #13119 from sbagdat/patch-1

Update render with a spacer_template [ci skip]
Improve changelogs [ci skip]
Use genderless pronouns in API docs