Trac #16293: Fix sage-cleaner's rm_rf function on OS X

On OS X, if you use `os.unlink` on a directory, you get an OSError,
"[Errno 1] Operation not permitted". We need to catch this so that
`sage-cleaner` works properly. (On linux machines, you seem to get
OSError, "[Errno 21] Is a directory".)

URL: http://trac.sagemath.org/16293
Reported by: jhpalmieri
Ticket author(s): John Palmieri
Reviewer(s): Leif Leonhardy

src/bin/sage-cleaner

@@ -51,7 +51,7 @@ def rm_rf(file_or_path):
     try:
         os.unlink(file_or_path)
     except OSError as e:
-        if e.errno == errno.EISDIR:
+        if e.errno == errno.EISDIR or e.errno == errno.EPERM:
             shutil.rmtree(file_or_path, ignore_errors=True)