[ci skip] Mention the change in nil handling for serialized attributes
in "Upgrading from Rails 3.2 to Rails 4.0"
[ci skip] Clarify the "Serialized Attributes" section

Mention that the change in nil handling for serialized attributes
affects custom coders.
Fixes to TestCaseTest.
Retrieve source code for the entire stack trace

Provide the ability to extract the source code of the entire exception stack
trace, not just the frame raising the error. This improves debugging
capability of the error page, especially for framework-related errors.
Update actionpack CHANGELOG
[ci skip] Changed 'first argument' to '+name+ argument'
Merge pull request #16428 from tomkadwill/activerecord_associations_name_param

[ci skip] Changed 'first argument' to '+name+ argument'
Fix typo in plugins doc
Merge pull request #16430 from guillermo/patch-1

Fix typo in plugins doc
Fix the #const_regexp's documentation [ci skip]

Originally introduced in f9086d63, the documentation of this method is
wrong as #const_regexp returns a string to easy the interpolation inside
regular expressions.
Merge pull request #16426 from tgxworld/fix_false_positive

Fixes to TestCaseTest.
Merge pull request #16427 from ryandao/full_stack_source_extract

Full stack source extract
Fixes test for Gemfile entry changes

Broken by fbe38c9e9d4fe9f82518e8ffc1d757459b0c5f1c
Merge pull request #16429 from arunagw/aa-build-fix-gemfile-spring

Fixes test for Gemfile entry changes
add a test for prepending SCRIPT_NAME to generated urls
save a hash allocation per request.
Add config option for cookies digest

You can now configure custom digest for cookies in the same way as `serializer`:

config.action_dispatch.cookies_digest = \SHA256'
Return preconfigured AS::MessageVerifier
Merge pull request #16434 from strzalek/cookies-digest-config-option

Add digest config option for SignedCookiesJar
Revert "Merge pull request #16434 from strzalek/cookies-digest-config-option"

This reverts commit 705977620539e2be6548027042f33175ebdc2505, reversing
changes made to dde91e9bf5ab246f0f684b40288b272f4ba9a699.

IT BROKE THE BUILD!!!