Merge pull request #282 from gregquat/origin/2.3

Updating reference/form/types/* from symfony-docs/2.3
Add files in references types options
Merge pull request #284 from StefTweet/2.3

Add files in references types options
Merge pull request #285 from StefTweet/2.3

Add files in references types options
updating from symfony-docs 2.3
Merge pull request #286 from gregquat/origin/2.3

Updating book and installation
Update security.rst

typo on line 1601 : "c'e'st" should be "c'est"
on book 2.2 and 2.3
Merge pull request #288 from beesofts/patch-1

Update security.rst
Update testing.rst

$client->getResponse()->getStatus() 
should be 
$client->getResponse()->getStatusCode() on line 307 
(already corrected on english version)
Merge pull request #289 from beesofts/master

Update testing.rst