Correcting a NPE where the user had no .minecraft whatsoever.

I saw a bug report (thankfully a stacktrace) that indicated that Arrays.sort() doesn't like empty File[]. base.listFiles() doesn't guarantee that it'll even fill the array if there's no files in the directory (for example, .minecraft doesn't exist). I've shifted the Array.sort after the "Is files == null" check . I should have caught this, but I'm glad I have caught it now. This should fix bug #42 and make for happy people.

Regards, The Viking (Dr Smokey)