Ignore all attribute changes

This fixes an issue on Mac OS where Spotlight makes attribute changes to
files after each change (after a small delay), triggering reflex
multiple times.

I think it's intuitive that attr changes wouldn't trigger reflex. If
this turns out not to be true, we can be more selective about ignoring
events in the future.

Fixes issue #11.

workers.go

@@ -73,6 +73,9 @@ func watch(root string, watcher *fsnotify.Watcher, names chan<- string, done cha
 			if verbose {
 				infoPrintln(-1, "fsnotify event:", e)
 			}
+			if e.IsAttrib() {
+				continue
+			}
 			names <- path
 			if e.IsCreate() {
 				if err := filepath.Walk(path, walker(watcher)); err != nil {