change to Symfony >=2.3.0,<2.4.0
Merge branch 'master' into symfony-2.3

* master:
  use self.version for Kunstmaan Bundles
  Symfony 2.2 and Kunstmaan bundles 2.2.8.* dependency
  implementation of the checkbox pagepart
  composer fix
  fix typo
  Update composer.json

Conflicts:
	composer.json
updated doc
Merge pull request #56 from Kunstmaan/symfony-2.3

Symfony 2.3