ActionMailer::Collector should be nodoc'd
Document ActionMailer::LogSubscriber and ActionMailer::DeliveryMethods::ClassMethods
Document ActionMailer::MailHelper
Removed incorrect warning from application.js templates and replaced it with stub command description
nodoc ActionMailer module from lib/action_mailer/*.rb
Document Rails::Generators::MailerGenerator
Merge pull request #10626 from firedev/master

Removed incorrect warning from application.js templates and replaced it with stub command description
change to destructive `deep_symbolize_keys` after https://github.com/rails/rails/commit/df24b8790f22384a068fece7042f04ffd2fcb33e which allows to do so. This helps to avoid extra hash object creation, by symbolizing inplace
Added documentation for ActiveRecord::Associations::Builder::Association class
Fixes bug 10628.
Added some more documentation for ActiveRecord::Associations::Builder::Association class
Added some more documentation for define_readers and define_writer of the Association and its inherited classes
restore ability to return nil from asset_host proc, add test
Rewrite `activerecord/RUNNING_UNIT_TESTS`

`RUNNING_UNIT_TESTS` is written in an unclear and confusing manner. This commit
attempts to correct that.

Thanks to zzak and vipulnsward for feedback.
Fix HWIA#to_hash behavior with array of hashes.
Merge pull request #10601 from Ichimonji10/fix-docs

Rewrite  `activerecord/RUNNING_UNIT_TESTS.rdoc`
Merge pull request #10631 from kennyj/improve_10266

Fix HWIA#to_hash behavior with array of hashes.
use unless instead of if!
simplify the condions lambda generation
conditions are guaranteed to be arrays by initialize