New make:serializer:normalizer command and other minor new features

Another release to make developing in Symfony faster! Highlights:

• Add make:serializer:normalizer command - #298 thanks
  to @lyrixx

• Add a --no-template option to make:controller to skip
  generating a template - #280 thanks to @welcoMattic

• Add support for rendering additional date types in make:crud

  • #241 thanks to @sadikoff

• Better errors when trying to use reserved words for classes

  • #306 thanks to @SerkanYildiz