[Intl] Integrated ICU data into Intl component
updated CHANGELOG for 2.3.20
update CONTRIBUTORS for 2.3.20
updated VERSION for 2.3.20
bumped Symfony version to 2.3.21
[Validator] Update validators.zh_CN.xlf, fix translation error
minor #12070 [Validator] Update validators.zh_CN.xlf, fix translation error (michaeljayt)

This PR was submitted for the master branch but it was merged into the 2.3 branch instead (closes #12070).

Discussion
----------

[Validator] Update validators.zh_CN.xlf, fix translation error

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

Commits
-------

ab5aaab [Validator] Update validators.zh_CN.xlf, fix translation error
[EventDispatcher] fix doc bloc on EventDispatcherInterface
minor #12080 [EventDispatcher] fix doc bloc on EventDispatcherInterface (nicolas-grekas)

This PR was merged into the 2.3 branch.

Discussion
----------

[EventDispatcher] fix doc bloc on EventDispatcherInterface

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

The doc block says that an array of event names is accepted as input, but no implementation is compliant with that description.

Commits
-------

e3dacbd [EventDispatcher] fix doc bloc on EventDispatcherInterface
bug #11920 [Intl] Integrated ICU data into Intl component #1 (webmozart)

This PR was merged into the 2.3 branch.

Discussion
----------

[Intl] Integrated ICU data into Intl component #1

| Q             | A
| ------------- | ---
| Bug fix?      | no
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | #11447, #10807
| License       | MIT
| Doc PR        | -

This PR is an alternative implementation to #11884. It depends on ~~#11906~~ and ~~#11907~~ being merged first (~~these are included in the diff until after a merge+rebase~~ merged+rebased now).

With this PR, the ICU component becomes obsolete. The ICU data is bundled with Intl in two different formats: JSON and the binary ICU resource bundle format (version 2) readable by PHP's `\ResourceBundle` class. For a performance comparison between the two, see my [benchmark](/webmozart/json-res-benchmark).

~~The data is contained in two zip files: json.zip (2.6MB) and rb-v2.zip (3.8MB). The handler~~

```php
\Symfony\Component\Intl\Composer\ScriptHandler::decompressData()
```

~~needs to be added as Composer hook and decompresses the data after install/update.~~

The data is included as text/binary now. Git takes care of the compression.

Before this PR can be merged, I would like to find out what the performance difference between the two formats is in real applications. For that, I need benchmarks from some real-life applications which use ICU data - e.g. in forms (language drop-downs, country selectors etc.) - for both the JSON and the binary data. You can force either format to be used by hard-coding the return value of `Intl::detectDataFormat()` to `Intl::JSON` and `Intl::RB_V2` respectively. I'll also try to create some more realistic benchmarks.

If JSON is not significantly slower/takes up significantly more memory than the binary format, we can drop the binary format altogether.

Commits
-------

be819c1 [Intl] Integrated ICU data into Intl component
[Intl] Generated the data for ICU version 54-rc
bug #11998 [Intl] Integrated ICU data into Intl component #2 (webmozart)

This PR was submitted for the master branch but it was merged into the 2.3 branch instead (closes #11998).

Discussion
----------

[Intl] Integrated ICU data into Intl component #2

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

Follow-up PR to #11920. This PR contains generated data files only.

Commits
-------

65a8b9f [Intl] Generated the data for ICU version 54-rc
[Intl] FIxed failing test
fix components tests

Since #12006, the `ContainerBuilder` contains the
`addExpressionLanguageProvider()` method which references a class from
the ExpressionLanguage component. By default, the PHPUnit mock API
tries to mock all methods of the class being doubled. Since the
ExpressionLanguage component is not required to run the tests,
creating the mock objects fails when the mock API fails to mock
the `addExpressionLanguageProvider()` method.
minor #12088 fix components tests (xabbuh)

This PR was merged into the 2.3 branch.

Discussion
----------

fix components tests

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

Since #12006, the `ContainerBuilder` contains the `addExpressionLanguageProvider()` method which references a class from the ExpressionLanguage component. By default, the PHPUnit mock API tries to mock all methods of the class being doubled. Since the ExpressionLanguage component is not required to run the tests, creating the mock objects fails when the mock API fails to mock the `addExpressionLanguageProvider()` method.

Commits
-------

2f2a732 fix components tests
[Finder] Add info about possibilities offered by SplFileInfo
minor #12059 [Finder] Add info about possibilities offered by SplFileInfo (ywarnier)

This PR was submitted for the master branch but it was merged into the 2.3 branch instead (closes #12059).

Discussion
----------

[Finder] Add info about possibilities offered by SplFileInfo

Minor documentation improvement

Commits
-------

b2219cf [Finder] Add info about possibilities offered by SplFileInfo
[Finder] tweaked docs
[Doc] Use Markdown syntax highlighting
Merge branch 'pull/12053' into 2.3

* pull/12053:
  [Doc] Use Markdown syntax highlighting

Conflicts:
	src/Symfony/Component/Finder/README.md