use meta charset in layouts without legacy http-equiv
[TwigBundle] remove unused email placeholder from error page
[TwigBundle] show correct fallback exception template in debug mode
[TwigBundle] do not pass a template reference to twig

twig does not know about template references and only expects a string.
this commit also fixes that name parsing and locating was called twice for nonexistent templates
bug #12197 [TwigBundle] do not pass a template reference to twig (Tobion)

This PR was merged into the 2.3 branch.

Discussion
----------

[TwigBundle] do not pass a template reference to twig

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

twig does not know about template references and only expects a string.
this commit also fixes that name parsing and locating was called twice for nonexistent templates.

Commits
-------

7fe33e3 [TwigBundle] do not pass a template reference to twig
minor #12193 [TwigBundle] remove unused email placeholder from error page (Tobion)

This PR was merged into the 2.3 branch.

Discussion
----------

[TwigBundle] remove unused email placeholder from error page

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

remove unused email placeholder from error page

Commits
-------

a64bd03 [TwigBundle] remove unused email placeholder from error page
Merge branch '2.3' into 2.5

* 2.3:
  enforce memcached version to be 2.1.0
  [FrameworkBundle] improve server:run feedback
  [Form] no need to add the url listener when it does not do anything
  [Form] Fix #11694 - Enforce options value type check in some form types
  Lithuanian security translations
  [Router] Cleanup
  [FrameworkBundle] Fixed ide links
  Add missing argument
  [TwigBundle] do not pass a template reference to twig
  [TwigBundle] show correct fallback exception template in debug mode
  [TwigBundle] remove unused email placeholder from error page
  use meta charset in layouts without legacy http-equiv

Conflicts:
	src/Symfony/Bundle/TwigBundle/Loader/FilesystemLoader.php
	src/Symfony/Bundle/TwigBundle/Resources/views/layout.html.twig