Extract new base test class KernelTestClass

Ideal base class that needs access to a Kernel but not a Client such as
when testing a Command.
[Form] Changed Form::getErrors() to return an iterator and added two optional parameters $deep and $flatten
[Form] Changed the default value of $flatten in Form::getErrors() to true
[2.4][HttpKernel] Fix issue #10209
When the profiler has `only_exception` option activated and a subrequest
throw an exception, the parent profile cannot be found.

| Q             | A
| ------------- | ---
| Bug fix?      | yes
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| License       | MIT
Follow-up to #10312: Fixed minor performance related issues in Yaml\Inline.
minor #10323 [Yaml] Fixed minor performance related issues in Yaml\Inline. (sun)

This PR was submitted for the 2.3-dev branch but it was merged into the 2.3 branch instead (closes #10323).

Discussion
----------

[Yaml] Fixed minor performance related issues in Yaml\Inline.

Follow-up to #10312

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

Commits
-------

a36fef5 Follow-up to #10312: Fixed minor performance related issues in Yaml\Inline.
Fixed evaluation of short circuit operators
bug #10338 [ExpressionLanguage] Fixed evaluation of short circuit operators (florianv)

This PR was submitted for the 2.4-dev branch but it was merged into the 2.4 branch instead (closes #10338).

Discussion
----------

[ExpressionLanguage] Fixed evaluation of short circuit operators

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

Commits
-------

fba0a40 [ExpressionLanguage] Fixed evaluation of short circuit operators
Throw exception when unable to normalize embedded object

Added a check to ensure that injected serializer of the
GetSetMethodNormalizer is a normalizer before normalizing object value.
bug #10306 [Serializer] Throw exception when unable to normalize embedded object (gquemener)

This PR was submitted for the 2.1 branch but it was merged into the 2.4 branch instead (closes #10306).

Discussion
----------

[Serializer] Throw exception when unable to normalize embedded object

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

This PR intends to prevent Fatal Error about calling undefined method `normalize()` on object `$serializer` in the `GetSetMethodNormalizer` when injected serializer does not implement the `NormalizerInterface`.

Commits
-------

8a54920 [Serializer] Throw exception when unable to normalize embedded object
updated CHANGELOG for 2.3.11
update CONTRIBUTORS for 2.3.11
updated VERSION for 2.3.11
bumped Symfony version to 2.3.12
Merge branch '2.3' into 2.4

* 2.3:
  bumped Symfony version to 2.3.12
  updated VERSION for 2.3.11
  update CONTRIBUTORS for 2.3.11
  updated CHANGELOG for 2.3.11
  Follow-up to #10312: Fixed minor performance related issues in Yaml\Inline.

Conflicts:
	src/Symfony/Component/HttpKernel/Kernel.php
Update FileLoader to fix issue #10339

FileLoader now uses resolved FileLoader's (the one that explicitly
supports that resource) FileLocatorInterface instance before falling
back to its own when trying to load resources in import() method.
bug #10348 Update FileLoader to fix issue #10339 (msumme)

This PR was merged into the 2.3 branch.

Discussion
----------

Update FileLoader to fix issue #10339

This fixes an issue in Symfony\Component\Config\Loader\FileLoader

| Q             | A
| ------------- | ---
| Bug fix?      |  yes
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets |  #10339
| License       | MIT
| Doc PR        |  none

Commits
-------

3988728 Update FileLoader to fix issue #10339
added a BC comment
Improves the readability of the collected arrays in the profiler.
fixed Kernel::stripComments() normalizing new-lines

This makes normalizing new-lines less error-prone
when a string contains multiple new line-lines