Merge branch '2.3' into 2.4

* 2.3:
  Fixed mistake in upgrade docu
  Container::camelize also takes backslashes into consideration
  fixed typos
  fixed @ExpectedException class names
  fixed some typos
  fixed @ExpectedException class names
  Typo and better wording for german validator translation

Expression/Expression.php

@@ -130,7 +130,7 @@ public function isGlob()
     public function getGlob()
     {
         if (self::TYPE_GLOB !== $this->value->getType()) {
-            throw new \LogicException('Regex cant be transformed to glob.');
+            throw new \LogicException('Regex can\'t be transformed to glob.');
         }
 
         return $this->value;