reproduced JENKINS-17545 in unit test
fixed JENKINS-17545 : reusing matchingFilesFrom() method for matches() implementation in PatternsEntityMatcher
In this way, we should avoid the different behaviour DirectoryScanner.match() has (concerning wildcards) compared to scan() with includes
fixed HudsonExtensionsTest.shouldFileWhichHaveToBeInSCM() regression by providing a fake file hierarchy containing files tested in the test