FriendsOfSymfony/FOSUserBundle — pull request #1613 by stof (2014-09-26 21:39:07+00:00)
Title: Removed the option to switch to a different templating engine

This option was introduced in the early days of the Symfony development when Twig was not yet the recommended engine, to let users remove the dependency on Twig at the expense of rewriting all templates for their engine.
Making the code ugly and inconsistent with the Symfony ecosystem to implement a feature which is barely usable is not worth it.