Merge branch '4.2' into 4.3

* 4.2:
  [Routing] Fixed unexpected 404 NoConfigurationException
  [DI] Removes number of elements information in debug mode
  [Contracts] Simplify implementation declarations
  Update PR template for 4.3
  [Intl] Add FallbackTrait for data generation
  [Console] Commands with an alias should not be recognized as ambiguous
  clarify the possible class/interface of the cache

Author: nicolas-grekas

composer.json

@@ -40,7 +40,7 @@
     },
     "provide": {
         "psr/container-implementation": "1.0",
-        "symfony/service-contracts-implementation": "1.0"
+        "symfony/service-implementation": "1.0"
     },
     "autoload": {
         "psr-4": { "Symfony\\Component\\DependencyInjection\\": "" },