Return BC compatibility for `@Route` parameters and default values
[Serializer] Added XML attributes support for DomDocument in XmlEncoder.

This is a combination of 2 commits.

- [Serializer] Added encoding support for DomDocument in XmlEncoder

- [Serializer] Refactor code to allow setting <?xml standalone ?>

This commit refactors the createDomDocument(..) method in XmlEncoder
so
it can set the 'version', 'encoding' and 'standalone' attributes on
the
DOM document.

Code coverage of new code: 100%. Tests: pass.
Ignore null value in comparison validators
merged branch fabpot/console-fix (PR #8600)

This PR was merged into the 2.3 branch.

Discussion
----------

[FrameworkBundle] fixed regression where the command might have the wrong container if the application is reused several times

Commits
-------

1bd45b3 [FrameworkBundle] fixed regression where the command might have the wrong container if the application is reused several times
[HttpFoundation] deprecated FlashBag::getIterator() method
[WebProfilerBundle] made toolbar listener instantiation conditional
[Console] fixed tests
Revert "[Form] Remove "value" attribute on empty_value option"

This reverts commit 9e849eb78bcc668a2b8aad39cb47e2ad32c73a47.

Reasons for the revert:

* https://github.com/symfony/symfony/issues/8478
* https://github.com/symfony/symfony/issues/8526
Fixes link indices
[Form] Changed (Number|Integer)ToLocalizedStringTransformer::reverseTransform() to do rounding
[Form] Fixed: If a form is not present in a request, it is not automatically submitted
Revert "[Form] Fix of "PATCH'ed forms are never valid""

This reverts commit a2b15359d81563d52b62b4357407efa949a0706a.

Conflicts:
	src/Symfony/Component/Form/Form.php

The commit is reverted because it introduces a bug demonstrated by a currently failing test.
[Form] Fixed patched forms to be valid even if children are not submitted
merged branch jfsimon/fix-tests (PR #8618)

This PR was merged into the master branch.

Discussion
----------

[Console] fix tests

| Q             | A
| ------------- | ---
| Bug fix?      | no
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes

Commits
-------

e4c1b30 [Console] fixed tests
merged branch jfsimon/issue-8130 (PR #8615)

This PR was merged into the master branch.

Discussion
----------

[WebProfilerBundle] make toolbar listener instantiation conditional

In the `WebProfilerBundle`, if `intercept_redirects` and `toolbar` options are both `false`, the `toolbar.xml` config file should not be loaded as the listener becomes useless.

| Q             | A
| ------------- | ---
| Bug fix?      | no
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | #8130

Commits
-------

17cbfc8 [WebProfilerBundle] made toolbar listener instantiation conditional
merged branch jfsimon/issue-8294 (PR #8611)

This PR was merged into the master branch.

Discussion
----------

[HttpFoundation] deprecates FlashBag::getIterator() method

This PR does not fix #8294 but this issue is not fixable. The `FlashBag::getIterator()` method actualy does not make any sense and is confusing. It should be removed. I just added a `@deprecated` tag and `Will be removed in 3.0.` message because removing it now would introduce a BC break. I guess issue #8294 can be closed after merge as it make not more sense than the incriminated method.

| Q             | A
| ------------- | ---
| Bug fix?      | no
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | #8294

Commits
-------

ce8a7d6 [HttpFoundation] deprecated FlashBag::getIterator() method
merged branch bschussek/revert-7678 (PR #8623)

This PR was merged into the 2.3 branch.

Discussion
----------

Revert "[Form] Remove "value" attribute on empty_value option"

| Q             | A
| ------------- | ---
| Bug fix?      | yes (together with #8622)
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | #7678 #8478 #8526
| License       | MIT
| Doc PR        | -

Commits
-------

dbd14fc Revert "[Form] Remove "value" attribute on empty_value option"
merged branch langj/readme-link-fix (PR #8632)

This PR was merged into the 2.3 branch.

Discussion
----------

Fixes link indices

Fixes links in the symfony/intl README.md

Commits
-------

d1e5710 Fixes link indices
Merge pull request #8634 from bschussek/issue8473

[Form] Changed (Number|Integer)ToLocalizedStringTransformer::reverseTransform() to do rounding
merged branch bschussek/issue8385 (PR #8636)

This PR was merged into the 2.3 branch.

Discussion
----------

[Form] Fixed: If a form is not present in a request, it is not automatically submitted

| Q             | A
| ------------- | ---
| Bug fix?      | yes
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | #8385
| License       | MIT
| Doc PR        | -

This PR changes the following behavior of `handleRequest()`:

Current behavior:

```php
$_POST = array('foo' => 'bar');
$form = $factory->createNamed('myform', 'mytype');

// "myform" is not present in the request
$form->handleRequest();

assert(true === $form->isSubmitted());
```

Behavior after PR:

```php
$_POST = array('foo' => 'bar');
$form = $factory->createNamed('myform', 'mytype');

// "myform" is not present in the request
$form->handleRequest();

assert(false === $form->isSubmitted());
```

As #8385 pointed out, the latter behavior is expected, so I consider the current behavior a bug.

Commits
-------

cb5e765 [Form] Fixed: If a form is not present in a request, it is not automatically submitted