Fixes #6156 Redirect /index.php/.whatever?... to /index.php?...

/index.php/.html?... URLs can be interpreted by old browsers using the extension instead of the Content-Type header. This redirection should prevent that.
Added tests for #6156: test that correct urls are not redirected
Merge branch 'master' into bugfix/6156
Moved the FrontControllerTest following the tests reorganization
Refactored #6404 into a separate UrlFilter class with dedicated unit tests
Renamed UrlFilter to Router
Merge branch 'master' into bugfix/6156
Added missing @group annotations
Forgot renaming a test class
Revert previous commit (committed to fast -_-)
Fixed a bug in Url: the PATH_INFO was dropped

Fixed getCurrentUrl() and getCurrentUrlWithoutQueryString() + tests
Made FrontController use Url::getCurrentUrl()
Added missing @group annotations in tests
refs #6444 when copy a php file check whether it was actually copied and whether they have same content. Wondering about problems re using different filesystems for tmp and other directories and whether opcache causes any problems but should not
refs #6444 if it fails to copy the first time, try it another time before triggering the error
Merge branch 'master' into bugfix/6156
Fixing tests
Fixing nginx config for the tests so that it matches all URLs like Apache (for testing wrong urls in the tests)
Merge branch 'master' into bugfix/6156
Use the SystemTestCase as the base test class for the FrontControllerTest