SQLite3Adapter now checks for views in table_exists? fixes: 14041
Updating Associations::Preloader docs

Much of the previous documentation introduced features new in 2011. This
commit refreshes it to provide clearer code examples and spends more
time describing the normal case (preloaded associations) and less time
describing the fallback.

[ci skip]
Roll back open transactions when the running thread is killed.
Use the released jquery-rails gem
Dependencies: bump to jquery-rails 4.0.0.beta2
fix the undefined method content_tag #15245
not required include ActionView::Helpers::TagHelper in test as well
Deprecate implicit AD::Response splatting and Array conversion
Merge pull request #16822 from jeremy/deprecate-problematic-implicit-response-splatting

Deprecate implicit AD::Response splatting and Array conversion
Merge pull request #16824 from rajcybage/action_view_content_tag

fix the undefined method content_tag #15245
Dynamically modified schema and association would not be correctly reset

This fixes <"SQLite3::SQLException: no such column: legacy_things.person_id: SELECT \"legacy_things\".* FROM \"legacy_things\" WHERE \"legacy_things\".\"person_id\" = ?">
in OptimisticLockingTest#test_lock_destroy
disable migrations logging while running test cases for AR schema tests
Add support for Rack::ContentLength middelware
Fix query with nested array in Active Record

`User.where(id: [[1,2],3])` was equal to `User.where(id:[1, 2, 3])`
in Rails 4.1.x but because of some refactoring in Arel this stopped
working in 4.2.0. This fixes it in Rails.

[Dan Olson & Cristian Bica]
Merge pull request #16793 from javan/comply_with_rack_content_length_middleware

Add support for Rack::ContentLength middelware
Ignore segfault build errors with 2.0.0 + mysql-ruby

Continuation of c9a43126c5e2c608ab3ff1be994bce69e815a144

:cry:
[guides] Use `match ..., via: :all` in the custom exceptions app [ci skip]

Using `get` results in an unexpected error page(returning empty body) for requests of other HTTP mehtods other than GET. Use `match ..., via:
:all` so the exceptions app can be more stable.
Merge pull request #16832 from yuki24/use-match-via-all-in-custom-exceptions-app

[guides] Use `match ..., via: :all` in the custom exceptions app [ci skip]
Convert string concatenations to substitutions
Prefer "if any?" to "unless empty?"

* Consistent whitespace
* Remove unnecessary parentheses
Fix warnings for undefined local variable

* Add private method primary_key_for, which more clearly shows that the
expected return value is nil when a primary key is not found.