TYPO3 Core

t3lib_utility_Mail used callUserFunc for a hook. This hook was used to reroute all mails from that class to the new Swift Mailer. The result was an ugly class name and pretty messy code.
Ingo Renner supplied a nice interface and modified the hook to allow clean use of that interface.
Changes of issue 16879 are included in this rewrite.
A small fix for quoted display names is included.
Some lengthy pieces of code and repeating code were moved to separate methods.

Maybe t3lib/mail/class.tx_t3lib_mail_hooks.php needs to be renamed to t3lib/mail/class.t3lib_mail_swiftmaileradapter.php before applying the patch.
Furthermore this file had Windows line endings; these have been changed to Unix line endings. Maybe this needs to be done before applying the patch if errors about failing chunks appear
(issue imported from #M16911)