Cast the group name as a string

This allows the options to be grouped by association fields.
bug #10416 [Form] Allow options to be grouped by objects (felds)

This PR was submitted for the 2.3-dev branch but it was merged into the 2.3 branch instead (closes #10416).

Discussion
----------

[Form] Allow options to be grouped by objects

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

Commits
-------

ae3f02f Cast the group name as a string
Clean KernelInterface docblocks

- Fixed questionable grammar
- Added missing periods to make it consistent
minor #10525 [HttpKernel] Clean KernelInterface docblocks (sbward)

This PR was submitted for the 2.3-dev branch but it was merged into the 2.3 branch instead (closes #10525).

Discussion
----------

[HttpKernel] Clean KernelInterface docblocks

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

- Fixed questionable grammar
- Added missing periods to make it consistent

Commits
-------

4b1f050 Clean KernelInterface docblocks
fixed comment in forms.xml file
minor #10514 [FrameworkBundle] fixed comment in forms.xml file (hhamon)

This PR was merged into the 2.3 branch.

Discussion
----------

[FrameworkBundle] fixed comment in forms.xml file

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

Commits
-------

f9f7246 [FrameworkBundle] fixed comment in forms.xml file
Update OptionsResolver.php

Deleting an extra space in the exception.
minor #10528 Update OptionsResolver.php (shadypierre)

This PR was submitted for the 2.3-dev branch but it was merged into the 2.3 branch instead (closes #10528).

Discussion
----------

Update OptionsResolver.php

Deleting an extra space in the exception.

Commits
-------

7507fbb Update OptionsResolver.php
removed ini check to make uploadedfile work on gae
bug #9784 [HttpFoundation] Removed ini check to make Uploadedfile work on Google App Engine (micheleorselli)

This PR was submitted for the master branch but it was merged into the 2.3 branch instead (closes #9784).

Discussion
----------

[HttpFoundation] Removed ini check to make Uploadedfile work on Google App Engine

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

related to #9238

Commits
-------

ecb6481 removed ini check to make uploadedfile work on gae
Fix libxml_use_internal_errors and libxml_disable_entity_loader usage
bug #10493 [2.3] Fix libxml_use_internal_errors and libxml_disable_entity_loader usage (romainneutron)

This PR was merged into the 2.3 branch.

Discussion
----------

[2.3] Fix libxml_use_internal_errors and libxml_disable_entity_loader usage

| Q             | A
| ------------- | ---
| Bug fix?      | yes
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | #9731, #9483
| License       | MIT

This should fix #9731 and #9483 that seems to be triggered when `libxml_disable_entity_loader` has been called with `true` (see https://bugs.php.net/bug.php?id=62577)
As `libxml_disable_entity_loader` is non thread safe (see https://bugs.php.net/bug.php?id=64938) and as we have some calls that might leave the setting to `true`, I think the bug should be fixed.

I've checked the use of both `libxml_use_internal_errors` and `libxml_disable_entity_loader` among symfony code.

You can see I prefered to skip DomDocument::loadXML warnings using the `@` instead of using `LIBXML_NOERROR | LIBXML_NO_WARNING` because we can log these errors whereas libxml errors would be furtives.

 - [x] Check calls to DOMDocument::load
 - [x] Check calls to DOMDocument::loadXML
 - [x] Check calls to DOMDocument::loadHTML
 - [x] Check calls to DOMDocument::loadHTMLFile
 - [x] Add more tests

Commits
-------

489b8ae Fix libxml_use_internal_errors and libxml_disable_entity_loader usage
Fix #10437: Catch exceptions when reloading a no-cache request
bug #10502 [HttpKernel] Fix #10437: Catch exceptions when reloading a no-cache request (romainneutron)

This PR was merged into the 2.3 branch.

Discussion
----------

[HttpKernel] Fix #10437: Catch exceptions when reloading a no-cache request

| Q             | A
| ------------- | ---
| Bug fix?      | yes
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | #10437
| License       | MIT

Commits
-------

8e3a395 Fix #10437: Catch exceptions when reloading a no-cache request
Fix #8205 : Deprecate file mode update when calling dumpFile
bug #10532 Fixed regression when using Symfony on filesystems without chmod support (fabpot)

This PR was merged into the 2.3 branch.

Discussion
----------

Fixed regression when using Symfony on filesystems without chmod support

| Q             | A
| ------------- | ---
| Bug fix?      | yes
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | #8205
| License       | MIT
| Doc PR        | n/a

Commits
-------

cefb67a Fix #8205 : Deprecate file mode update when calling dumpFile
handle array root element

An array to string conversion notice was thrown when the root element of
the thing being validated is an array.
bug #10123 handle array root element (greg0ire)

This PR was submitted for the 2.4 branch but it was merged into the 2.3 branch instead (closes #10123).

Discussion
----------

handle array root element

An array to string conversion notice was thrown when the root element of the thing being validated is an array.

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

Commits
-------

17ed8bf handle array root element
Fixed ACE domain checks on UrlValidator (#10031)
bug #10275 [Validator] Fixed ACE domain checks on UrlValidator (#10031) (aeoris)

This PR was merged into the 2.3 branch.

Discussion
----------

[Validator] Fixed ACE domain checks on UrlValidator (#10031)

| Q             | A
| ------------- | ---
| Bug fix?      | yes
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | #10031
| License       | MIT
| Doc PR        |

I added some checks to allow internationalised domain names as per reported on #10031 and some extra testcases to cover ACE domain names.

Commits
-------

7a2f154 Fixed ACE domain checks on UrlValidator (#10031)