docs, Cookie values are String based. Closes #12860. [ci skip]
Rely on backticks instead of tt tags [ci skip]

Since the language in code blocks is inferred, if the code contains tt
tags, the block will be parsed as XML for instance while it is Ruby.
Updated the cookie docs to use the safer JSON.{generate,parse}

cc @senny
Add test case for autosave HasMany with accepts_nested_attributes.

It should not save the parent record when the nested attributes are
invalid.

Test case to cover #8194.
Merge pull request #13974 from laurocaetano/test_case_for_autosave_with_accepts_nested_attributes

Add test case for autosave association with nested attributes.
Fixed an issue where reloading of removed dependencies would cause an unexpected circular dependency error
Merge pull request #13977 from Octember/master

Fixed an issue where reloading of removed dependencies would cause an un...
Add missing test for response destructuring.
Prevent [response].flatten from recursing infinitely.

Returning `self` from within the array returned by `to_ary`
caused this. Instead, we can just substitute another object.
It provides the `each` behavior required by the rack spec.