updated version to 2.5
Merge branch '2.4'

* 2.4:
  [HttpKernel] fixed regression introduced in 2.4 in the base DataCollector class. Added more unit tests coverage for the RequestDataCollector object.
  Fixed mistake in upgrade docu
  bumped Symfony version to 2.4.0
  updated VERSION for 2.4.0-RC1
  updated CHANGELOG for 2.4.0-RC1
  Container::camelize also takes backslashes into consideration
  fixed typos
  fixed @expectedException class names
  Fix an issue when overriding Client::setServerParameters() and using the getContainer() method in it.
  fixed some typos
  fixed @expectedException class names
  Typo and better wording for german validator translation
Merge branch '2.4'

* 2.4:
  udpated LICENSE year
  update year on licenses
  rundown and typo fix
  [Process] Fix #9861 : Revert TTY mode
  [Form] Update minimal requirement in composer.json
  Fix Empty translations with Qt files
  [Console] Fixed command name guessing if an alternative is an alias.
  Update UPGRADE-2.3.md to account for #9388
  [WebProfilerBundle] Fixed profiler toolbar icons for XHTML.
  [BrowserKit] Throw exception on invalid cookie expiration timestamp
  [Propel1Bridge][ModelChoiceList] add exception message for invalid classes
Merge branch '2.4'

* 2.4:
  fixed various inconsistencies
  reduced recursion when building DumperPrefixCollection
  renamed variables - making next change more readable
  removing dead code.
  [ExpressionLanguage] added some tests for the built-in constant() function
  [ExpressionLanguage] added some documentation about functions
  [DomCrawler] Fixed filterXPath() chaining
  [DomCrawler] Fixed incorrect handling of image inputs
[ClassLoader] A PSR-4 compatible class loader
feature #10100 [ClassLoader] A PSR-4 compatible class loader (derrabus)

This PR was squashed before being merged into the 2.5-dev branch (closes #10100).

Discussion
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[ClassLoader] A PSR-4 compatible class loader

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

This is a PSR-4 compatible class loader that I'd like to contribute to the ClassLoader component. Since PSR-4 is the most recent FIG standard for an autoloader, I thought a compatible loader should be part of a feature-complete ClassLoader component.

See: http://www.php-fig.org/psr/psr-4/

PSR-4 does neither replace PSR-0, nor are those standards 100% compatible. This is why I implemented the standard as a new class.

If you decide that my PR is worth merging, I would also provide a PR for symfony-docs with a documentation.

Commits
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6837df3 [ClassLoader] A PSR-4 compatible class loader