Update MimeTypeExtensionGuesser.php

Fixed bug for MimeType `image/x-ms-bmp`
Merge branch '2.3' into 2.4

* 2.3:
  Update MimeTypeExtensionGuesser.php
  [Templating] PhpEngine should propagate charset to its helpers
  Fix ticket #10663 - Added setCharset method call to PHP templating engine.
  Changed the typehint of the EsiFragmentRenderer to the interface
  [Form] Improved test coverage of UrlType
  [BrowserKit] Fix #10641 : BrowserKit is broken when using ip as host

Conflicts:
	src/Symfony/Component/HttpKernel/Fragment/EsiFragmentRenderer.php
	src/Symfony/Component/Templating/PhpEngine.php