Merge branch '2.8' into 3.0

* 2.8:
  [Yaml] always restore the error handler in tests
  [FrameworkBundle] fix YAML syntax
  fix YAML syntax in functional tests config

src/Symfony/Bundle/FrameworkBundle/Tests/DependencyInjection/Fixtures/yml/assets.yml

@@ -1,7 +1,7 @@
 framework:
     assets:
         version: SomeVersionScheme
-        version_format: %%s?version=%%s
+        version_format: '%%s?version=%%s'
         base_urls: http://cdn.example.com
         packages:
             images_path:
@@ -11,7 +11,7 @@ framework:
                 base_urls: ["http://images1.example.com", "http://images2.example.com"]
             foo:
                 version: 1.0.0
-                version_format: %%s-%%s
+                version_format: '%%s-%%s'
             bar:
                 base_urls: ["https://bar2.example.com"]
             bar_null_version:

src/Symfony/Bundle/FrameworkBundle/Tests/DependencyInjection/Fixtures/yml/full.yml

@@ -13,7 +13,7 @@ framework:
         only_exceptions: true
         enabled: false
     router:
-        resource:     %kernel.root_dir%/config/routing.xml
+        resource:     '%kernel.root_dir%/config/routing.xml'
         type:         xml
     session:
         storage_id:      session.storage.native
@@ -48,7 +48,7 @@ framework:
     annotations:
         cache:   file
         debug:   true
-        file_cache_dir: %kernel.cache_dir%/annotations
+        file_cache_dir: '%kernel.cache_dir%/annotations'
     serializer:
          enabled:        true
          enable_annotations: true

src/Symfony/Bundle/SecurityBundle/Tests/Functional/app/config/twig.yml

@@ -3,5 +3,5 @@ framework:
 
 # Twig Configuration
 twig:
-    debug:            %kernel.debug%
-    strict_variables: %kernel.debug%
+    debug:            '%kernel.debug%'
+    strict_variables: '%kernel.debug%'