This reverts commit fa6d921e.

Reason: Not a fan of such massive changes. We usually close such changes
if made to Rails master as a pull request. Following the same principle
here and reverting.

[ci skip]

For future reference, this is the regex I used: ^\s*#\s*\n(?!\s*#). Replace
with the first match, and voilà! Note that the regex matches a little bit too
much, so you probably want to `git add -i .` and go through every single diff
to check if it actually should be changed.

closes #5970

one.

The latter doesn't render as code in HTML output.

Regex used in Rubymine to locate the latter form:

    (\+)(:*\w+:(?::|\w)+)(\+)

The release date details have been taken from
http://weblog.rubyonrails.org/2012/3/30/ann-rails-3-2-3-has-been-released/

  Second security vulnerability found in mail file delivery method
  patched in version 2.4.4.

the 1.9 hash syntax in the generators.

Prior to this commit, there isn't a good way of adding things like
default inline attachments to an email.  This Stack Overflow thread
shows people using hooks like the 'default' method in ActionMailer::Base
to call a Proc for message configuration:

http://stackoverflow.com/questions/5113121/rails-use-same-attachment-for-all-emails-using-layout

This has the unintended side effect of setting a message header, so it's not a good solution.

This pull request adds support for message modifications by including AbstractController:Callbacks
in ActionMailer::Base. It includes tests and documentation for the functionality
provided by including this module.

Also add missing entries and use the formating convention

Last commit message should not have said 'Rails 4' either

Increasing minimum version of mail due to security vulnerability found in Mail 2.4.1 for sendmail or exim

Closes #5025 part 2

See #3892

Proc#bind is not useful when called immediately and previous check for #call method is not correct