Refactoring of FileManagement branch with addition of a copyPathnames method

Not a request to merge just yet (I have tests to edit and write to confirm proper functionality) but I'm starting this pull request now, following a fresh push of my changes to this package moments earlier, to show that the FileManagement package is now able to accept a Set<Path> with one or more folder/file sources to be copied.  The Map<Path, BasicFileAttributes> returned by a FileEnumerator can be passed to the SwingFileManager's copyPathnames method by passing MapInstance.keySet().