[Security] Add SimpleForm authentication
[Security] Add simple_token auth method
[Security] Renamed simple_token to simple_http, added support for failure and success handler to both simple firewalls
fixed wrong Logger interface
moved the simple HTTP authenticator to a pre-auth one
[Security] allowed simple pre-auth to be optional if another auth mechanism already authenticated the user
marked some classes as being experimental in 2.3
[HttpFoundation][NamespacedAttributeBag] Refactoring of resolveKey() method
removed CHANGELOG for 2.0 as it is not maintained anymore
[Console] Added status code to CommandTester and ApplicationTester

Theses classes are already statefull. They contain the input and the
output data. So we can safely add the last status code to the class.
force the Content-Type to html in the web profiler controllers
Fix Crawler::children() to not trigger a notice for childless node
Merge branch '2.1' into 2.2

* 2.1:
  removed CHANGELOG for 2.0 as it is not maintained anymore

Conflicts:
	CHANGELOG-2.0.md
Merge branch '2.2'

* 2.2:
  removed CHANGELOG for 2.0 as it is not maintained anymore
updated version to 2.4
Revert "merged branch armetiz/master (PR #8045)"

This reverts commit a6dd5db60d1eb56be917fcc38244bcca168740a9, reversing
changes made to da6f190a6b630d6fc17729e04061308e573b47c7.
adding missing Farsi translations
merged branch empire/patch-validator-fa (PR #8060)

This PR was submitted for the master branch but it was merged into the 2.3 branch instead (closes #8060).

Discussion
----------

[Validator] added missing Farsi translations

| Q             | A
| ------------- | ---
| Fixed tickets | -
| License       | MIT

Farsi translations for the following validators

-  IBAN
-  ISBN
-  ISSN
-  Currency
-  EqualTo
-  IdenticalTo
-  NotEqualTo
-  NotIdenticalTo
-  GreaterThan
-  GreaterThanOrEqual
-  LessThan
-  LessThanOrEqual;

Commits
-------

026f2ac [Validator] adding missing Farsi translations
remove check for PHP bug #50731
merged branch xabbuh/issue8007-master (PR #8052)

This PR was submitted for the master branch but it was merged into the 2.3 branch instead (closes #8052).

Discussion
----------

remove check for PHP bug #50731

| Q             | A
| ------------- | ---
| Bug fix?      | no
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | #8007
| License       | MIT
| Doc PR        |

Commits
-------

28534a6 remove check for PHP bug #50731