This reverts commit 9cb1059f.

As discussed in #835 SOCKS5 supports IPv6 proxies and destinations.

...and removed some old ones

Follow-up to a96319eb (document the new behavior)

The server developer.netscape.com does not resolve into any
ip address and can be removed.

Added in 5fce88aa

After a few wasted hours hunting down the reason for slowness during a
TLS handshake that turned out to be because of TCP_NODELAY not being
set, I think we have enough motivation to toggle the default for this
option. We now enable TCP_NODELAY by default and allow applications to
switch it off.

This also makes --tcp-nodelay unnecessary, but --no-tcp-nodelay can be
used to disable it.

Thanks-to: Tim Rühsen
Bug: https://curl.haxx.se/mail/lib-2016-06/0143.html

Closes #835

Closes #768

Closes #662

Closes #885

merged #931

... and make the distros link a proper link

Closes https://github.com/curl/curl/pull/914

Explain how some FTP servers support the machine readable listing
format MLSD from RFC 3659 and compare it to LIST.

Ref: https://github.com/curl/curl/issues/906

Closes #896