[Validator] smaller fixes for binary format
[Validator] no need to initialize properties with null
minor #11140 [Validator] smaller CS fixes (Tobion)

This PR was merged into the 2.3-dev branch.

Discussion
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[Validator] smaller CS fixes

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

First commit fixes some CS of #11027
Second one removes `null` initialization from Validator as we don't do it.

Commits
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2025778 [Validator] no need to initialize properties with null
967576a [Validator] smaller fixes for binary format
Update WindowsPipes.php

This file has made that my assetic had an error, the property assignment have an extra "$" that it mustn't be present. Please correct it
bug #11156 Update WindowsPipes.php (jgonzalezlopez)

This PR was merged into the 2.6-dev branch.

Discussion
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Update WindowsPipes.php

This file has made that my assetic had an error, the property assignment have an extra "$" that it mustn't be present. Please correct it

Commits
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7bb98e2 Update WindowsPipes.php
[Debug] Symfony debug extension
[Debug] a README for the debug extension
[VarDumper] algo to clone any PHP variable to a breadth-first queue
[VarDumper] symfony_debug ext. fast and memory efficient cloning algo
[VarDumper] add casters for per class/resource custom state extraction
[VarDumper] casters for exceptions representation
[VarDumper] casters for SPL data structures
[VarDumper] Add workaround to https://bugs.php.net/65967
[VarDumper] casters for PDO related objects
[VarDumper] casters for removing the entity manager from Doctrine proxies
[VarDumper] interface for dumping collected variables
[VarDumper] CLI dedicated dumper and related abstract
[VarDumper] HTML variant of the CLI dumper
[VarDumper] spec for json based representation of PHP vars
[VarDumper] json dumper for interoperable displaying