Fix .update_all and .delete_all when using a condition on a joined table
in a default_scope.

`Model.joins(...).where(condition_on_joined_table).update_all` /
`delete_all` worked, but the same operation implemented with a
default_scope generated a SQL error because ActiveRecord ignored the
join but implemented the where condition anyways.
`CollectionAssociation#empty?` respects newly builded records
Fix ActionDispatch::Request#formats when HTTP_ACCEPT header is empty string
Remove i18n symbol dependency

date.order is the only key in rails i18n that is required to be a
symbol. This patch allows for symbols or strings which means:

* No requirement for symbol type in .yml files. A future
  YAML.safe_load wouldn't need to load symbols
* Rails could actually use json rather than yml as the backend
Don't change the original i18n data
Merge pull request #8912 from senny/8879_association_empty_method

`CollectionAssociation#empty?` respects newly builded records
CollectionProxy should be default scoped

Fixes #8795
Undeprecate the :extend option

Suggested by @dhh.

It doesn't affect the generated SQL, so seems reasonable to continue to
allow it as an association option.
User Rails 4 find_by
Merge pull request #8989 from robertomiranda/use-rails-4-find-by

Replace deprecated find_by_* with find_by
Revert "Merge pull request #8989 from robertomiranda/use-rails-4-find-by"

This reverts commit 637a7d9d357a0f3f725b0548282ca8c5e7d4af4a, reversing
changes made to 5937bd02dee112646469848d7fe8a8bfcef5b4c1.
MiniTest already defines a ParallelEach class

This may or may not fix the intermittent railties failures we've been
seeing on the CI with Ruby 2.0. We'll see.
The test setup is not threadsafe. Wrap in a mutex.
Merge pull request #8994 from Springest/fix_default_scope_update_all_delete_all

Fix .update_all and .delete_all when using a condition on a joined table in a default_scope
Remove "Application" section title from routes

This PR standardizes the output of the HTML and console based routes to not include the title for "Application Routes" those that are defined by the application. Instead only routes defined in engines get any special treatment. 

Based on this conversation:

https://github.com/rails/rails/commit/af5c0fd85fce1adb311083dd1ecf96432ee8caa3#commitcomment-2458823

ATP actionpack /cc @carlosantoniodasilva
Merge pull request #8995 from schneems/schneems/formatting-the-formatters

Remove "Application" section title from routes
Fix syntax error :grin:
Merge pull request #8977 from Soylent/master

Resovled issue rails#7774
Improve relation docs about to_sql and where_values_hash

* User class instead of Users.
* #where_values_hash does not change the value to downcase as the
  example was showing.

[ci skip]
Added ability to raise or log on unpermitted params.