filter out .DS_Store file name when looking for skins (created by Mac OS X Finder)

src/main/java/forge/view/toolbox/FSkin.java

@@ -67,6 +67,7 @@ public class FSkin {
         } else {
             for (int i = 0; i < children.length; i++) {
                 if (children[i].equalsIgnoreCase(".svn")) { continue; }
+                if (children[i].equalsIgnoreCase(".DS_Store")) { continue; }
                 mySkins.add(children[i]);
             }
         }