[2.3][EventDispatcher] Make events lighter
merged branch drak/edaware2 (PR #7852)

This PR was squashed before being merged into the master branch (closes #7852).

Discussion
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[2.3][EventDispatcher] Make events lighter

| Q             | A
| ------------- | ---
| Bug fix?      | no
| New feature?  | yes
| BC breaks?    | no
| Deprecations? | yes
| Tests pass?   | yes
| Fixed tickets | na
| License       | MIT
| Doc PR        | symfony/symfony-docs#2476

I've taken the previous discussions and taking into consideration @fabpot does not want to break BC. This PR now provides the `EventDispatcher` as an argument to listeners. I've made a second separate commit which also passes the event name.

This PR is alternative to #7582

Commits
-------

e2bff32 [2.3][EventDispatcher] Make events lighter
[EventDispatcher] fixed some phpdoc
updated the composer install command to reflect changes in Composer
Merge branch '2.2' into 2.3

* 2.2:
  Fix some annotates
  [FrameworkBundle] made sure that the debug event dispatcher is used everywhere
  [HttpKernel] remove unneeded strtoupper
  updated the composer install command to reflect changes in Composer

Conflicts:
	src/Symfony/Component/Console/Application.php
	src/Symfony/Component/Console/Command/Command.php
	src/Symfony/Component/Console/Input/InputDefinition.php
	src/Symfony/Component/CssSelector/Node/CombinedSelectorNode.php
	src/Symfony/Component/Form/Form.php
	src/Symfony/Component/HttpKernel/Debug/ErrorHandler.php
	src/Symfony/Component/HttpKernel/DependencyInjection/RegisterListenersPass.php
	src/Symfony/Component/HttpKernel/Tests/DependencyInjection/RegisterListenersPassTest.php
	src/Symfony/Component/Locale/Locale.php
	src/Symfony/Component/Locale/README.md
	src/Symfony/Component/Locale/Stub/DateFormat/FullTransformer.php
Merge branch '2.3'

* 2.3:
  fixed phpdoc
  Fix some annotates
  [FrameworkBundle] made sure that the debug event dispatcher is used everywhere
  [HttpKernel] remove unneeded strtoupper
  updated the composer install command to reflect changes in Composer

Conflicts:
	src/Symfony/Component/Serializer/Encoder/XmlEncoder.php