Merge branch '3.4' into 4.0

* 3.4:
  fixed wrong merge
  Tweak message to be Flex friendly
  [Routing] fixed tests
  Fixing wrong class_exists on interface
  Preserve percent-encoding in URLs when performing redirects in the UrlMatcher
  [Console] Fix a bug when passing a letter that could be an alias
  add missing validation options to XSD file
  Take advantage of AnnotationRegistry::registerUniqueLoader
  [DI] Optimize Container::get() for perf
  fix merge
  Fix tests
  Refactoring tests.

Author: fabpot

Tests/XPath/TranslatorTest.php

@@ -37,7 +37,7 @@ public function testXmlLang($css, array $elementsId)
         $translator = new Translator();
         $document = new \SimpleXMLElement(file_get_contents(__DIR__.'/Fixtures/lang.xml'));
         $elements = $document->xpath($translator->cssToXPath($css));
-        $this->assertEquals(count($elementsId), count($elements));
+        $this->assertCount(count($elementsId), $elements);
         foreach ($elements as $element) {
             $this->assertTrue(in_array($element->attributes()->id, $elementsId));
         }