[FrameworkBundle] Determine templating.engine.php scope as late as possible
feature #11961 [FrameworkBundle] Determine templating.engine.php scope as late as possible (lyrixx)

This PR was merged into the 2.6-dev branch.

Discussion
----------

[FrameworkBundle] Determine templating.engine.php scope as late as possible

| Q             | A
| ------------- | ---
| Bug fix?      | yes
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | #11653
| License       | MIT
| Doc PR        | -

Commits
-------

169dadd [FrameworkBundle] Determine templating.engine.php scope as late as possible