allow to register form types without extensions
Merge branch '1.2'

* 1.2:
  fixed CS
  Update session.rst
  updated docs and changelog
  Add  parameter for application middlewares (before, after, finish)
  updated docs and changelog
  allow to register form types without extensions

Conflicts:
	src/Silex/Provider/FormServiceProvider.php
	tests/Silex/Tests/Provider/FormServiceProviderTest.php