[DX] [Form] [WebProfiler] Added abbrs with type classes

This adds an <abbr> element having a descriptive title that
displays the form element's type class name.
[Form][WebProfiler] Empty form names fix

When a Form had no name, the markup was broken in the profiler,
making the form tree ugly.
Merge branch '2.5' into 2.6

* 2.5:
  reformat code as suggested by @fabpot
  Fix typo
  Make `\Request::get` more performant.
  [Form][WebProfiler] Empty form names fix
  [FrameworkBundle] cache:clear command fills *.php.meta files with wrong data
  bumped Symfony version to 2.5.8
  updated VERSION for 2.5.7
  update CONTRIBUTORS for 2.5.7
  updated CHANGELOG for 2.5.7
  bumped Symfony version to 2.3.23
  fixed typo
  updated VERSION for 2.3.22
  update CONTRIBUTORS for 2.3.22
  updated CHANGELOG for 2.3.22

Conflicts:
	src/Symfony/Bundle/WebProfilerBundle/Resources/views/Collector/form.html.twig
	src/Symfony/Component/HttpKernel/Kernel.php
Rename Symfony2 to Symfony
[WebProfilerBundle] Remove usage of app.request in search bar template
Merge branch '2.3' into 2.5

* 2.3:
  [Debug] fix error message on double exception
  Fix initialized() with aliased services
  Rename Symfony2 to Symfony
  backport #12489

Conflicts:
	CONTRIBUTING.md
	src/Symfony/Bundle/FrameworkBundle/Command/ServerRunCommand.php
	src/Symfony/Bundle/TwigBundle/Loader/FilesystemLoader.php
Merge branch '2.5' into 2.6

* 2.5:
  [Debug] fix error message on double exception
  Fix initialized() with aliased services
  Rename Symfony2 to Symfony
  compare version using PHP_VERSION_ID
  backport #12489
  remove an unneeded check
Merge branch '2.6' into 2.7

* 2.6: (36 commits)
  [Debug] fix error message on double exception
  [Validator] make DateTime objects represented as strings in the violation message.
  [RFC] [DebugBundle] [HttpKernel] Avoid using container as dependency for DumpListener
  Upgrade information for the Translation component regarding the new LoggingTranslator class.
  [WebProfilerBundle] Remove usage of app.request in search bar template
  Fix initialized() with aliased services
  fix data type in docblock
  Rename Symfony2 to Symfony
  bumped Symfony version to 2.6.0
  updated VERSION for 2.6.0-BETA2
  updated CHANGELOG for 2.6.0-BETA2
  [Debug] fix ENT_SUBSTITUTE usage
  compare version using PHP_VERSION_ID
  backport #12489
  remove an unneeded check
  Remove block submit_widget
  reformat code as suggested by @fabpot
  Fix typo
  Make `\Request::get` more performant.
  properly set request attributes in controller test
  ...