* 2.8:
Use the real image URL for the filesystem tests
[Finder] Update PHPdoc append()
[DI] Fix phpdoc
Fix code examples in PHPDoc
[HttpKernel] Fix inheritdocs
This method will be called before starting an authentication against a guard authhenticator.
The authentication will be tried only if the supports method returned <true>
This improves understanding of code, increase consistency and removes responsability for <getCredentials> method
To decide if the current request should be supported or not.
This looks like a subjective change (one more method, but the method implementations are
simpler), but it wasn't. The problem was that the UserChecker checkPreAuth should happen
*after* we get the user, but *before* the credentials are checked, and that wasn't possible
before this change. Now it is.