make doc ref example match the reSt standards
removed the $factory variable which is no longer needed in 2.2
Fixed a mistake in the docs about form creation

(you cannot simply call "->createForm()" in "any service that has access to the form factory")
Fixed typo
Explained a more simple method of dynamic form handling available since
https://github.com/symfony/symfony/pull/8827
Add missing configuration-block
Add missing slash in XML configuration
Merge pull request #2925 from xabbuh/fix-rest-example-standard

make doc ref example match the reSt standards
Merge branch 'dynamic_forms_after_PR8827' of github.com:Burgov/symfony-docs into Burgov-dynamic_forms_after_PR8827

Conflicts:
	cookbook/form/dynamic_form_modification.rst
[#2927] Tweaks to form events changes
Merge remote-tracking branch 'origin/2.2' into 2.2
Merge pull request #2930 from Burgov/remove_no_longer_necessary_factory

Remove no longer necessary factory
Merge pull request #2932 from WouterJ/fix_typo_redirectcontroller

Fix typo in Redirect Controller article
Merge branch '2.2' into 2.3

Conflicts:
	cookbook/form/dynamic_form_modification.rst