Add back FTP support

[K4sum1]

Again another it would be cool, but I'm not going to do it unless someone pr's it.

All related commits that I can find from bugzilla: https://hg.mozilla.org/mozilla-central/rev/a8489f281f78 https://hg.mozilla.org/mozilla-central/rev/bcdf1f609632 https://hg.mozilla.org/mozilla-central/rev/741e5111fa40 https://hg.mozilla.org/mozilla-central/rev/75fc5173b72d https://hg.mozilla.org/mozilla-central/rev/7ea6d7472432 https://hg.mozilla.org/mozilla-central/rev/fbe060c7c770 https://hg.mozilla.org/mozilla-central/rev/62a94cbcdb7e https://hg.mozilla.org/mozilla-central/rev/976bc7b343fb https://hg.mozilla.org/mozilla-central/rev/36ed59c135d9 https://hg.mozilla.org/mozilla-central/rev/cf0e44b8205e https://hg.mozilla.org/mozilla-central/rev/644af69790cb https://hg.mozilla.org/mozilla-central/rev/b52cf82fbe03 https://hg.mozilla.org/mozilla-central/rev/882c7f9567cd https://hg.mozilla.org/mozilla-central/rev/723c3f10571a https://hg.mozilla.org/mozilla-central/rev/3a28eb911d86 https://hg.mozilla.org/mozilla-central/rev/b73a08f694ec https://hg.mozilla.org/mozilla-central/rev/288c44b712b6 https://hg.mozilla.org/mozilla-central/rev/710df44e1a8d https://hg.mozilla.org/mozilla-central/rev/ec8d54876941 https://hg.mozilla.org/mozilla-central/rev/918cd3aff322 https://hg.mozilla.org/mozilla-central/rev/961a320a1d45 https://hg.mozilla.org/mozilla-central/rev/851056a4d881 https://hg.mozilla.org/mozilla-central/rev/6e22d16b03a3 https://hg.mozilla.org/mozilla-central/rev/05dcd8c1fee2 https://hg.mozilla.org/mozilla-central/rev/da90856e9854