Correct MKD, RMD, and DELE command replies per RFC959 (https://tools.ietf.org/html/rfc959#section-6).
Merge pull request #6 from k-anon/fix-extraneous-1xx

Correct DELE, MKD, and RMD Replies
Add support for file renaming (RNFR and RNTO)
Merge pull request #7 from yuriks/rnfr-rnto

Add support for file renaming (RNFR and RNTO)