[security] adding a tip about supported algorithm for 'hash' function
use a phpfunction link + vocabulary change (method -> function)
Change wording of voters
[Book][Validation] validate method in Validator returns ContraintViolationList object not an array
applies WouterJ suggestion
Small fixes
Documented CSRF protection in login forms
Added references
Removed all occurences of $this->getRequest()

The request is a data object, and so the request should not be
inside the container. That's why the request will be removed
from the container in Symfony 3.0

So it is better to let the HttpKernel injects the request when
the user want to use the request.

More over, it is faster. The HttpKernel will always check if the
request should be injected. So injecting the request is time constant.
However, retrieve the request from the container will execute more
calls.
Moved "Impersonating a User" to a cookbook entry
switch custom DQL code example from multi-manager to single
switch custom DQL code example from multi-manager to single (PHP and XML)
[#2362] Documentation for label_attr option in Form Compontent
Fixed comments
[Contributiong][Patches] Fix the broken tip about coding standards with ubot
Updated toctree and index
CaseFix
Expanded XML examples
Added `data` option to the "Inherited options" table.
Fixed sorting of options.
Made the note on selecting the checkbox by default more clear.
Added note on defaults to the `data` option partial.
Created consolidated "Access control" section; added warning about routing error pages