Closes #662

Closes #740

Closes #762

Closes #716

Closes #686 for now.

As of commit d9f3b365

Closes #750

Closes #603

Closes #544

Closes #543

Closes #522

Now sorted into categories and organized in the same style we do the
TODO document. It will make each issue linked properly on the
https://curl.haxx.se/docs/knownbugs.html web page.

The sections should make it easier to find issues and issues related to
areas of the reader's specific interest.

Bug: https://github.com/curl/curl/issues/536


Reported-by:  <eXeC64@users.noreply.github.com>

Due to their age (we don't fully know if they actually remain) and lack
of detail - very few people will bother to find out what they're about
or work on them. If people truly still suffer from any of these, I
assume they will be reported again and then we'll deal with them.

72. "Pausing pipeline problems."
  https://curl.haxx.se/mail/lib-2009-07/0214.html

70. Problem re-using easy handle after call to curl_multi_remove_handle
  https://curl.haxx.se/mail/lib-2009-07/0249.html

68. "More questions about ares behavior".
  https://curl.haxx.se/mail/lib-2009-08/0012.html

Closes #632

Closes #334

... since HTTP is forbidden to return any such.

This patch addresses known bug #76, where on 64-bit Windows SOCKET is 64
bits wide, but long is only 32, making CURLINFO_LASTSOCKET unreliable.

Signed-off-by: Razvan Cojocaru <rcojocaru@bitdefender.com>

Disabling pipelining on multi handle with in-progress pipelined requests
leads to heap corruption and crash

Use Unix when generically writing about Unix based systems as UNIX is
the trademark and should only be used in a particular product's name.

Problem: if CURLOPT_FORBID_REUSE is set, requests using NTLM failed
since NTLM requires multiple requests that re-use the same connection
for the authentication to work

Solution: Ignore the forbid reuse flag in case the NTLM authentication
handshake is in progress, according to the NTLM state flag.

Fixed known bug #77.

Reflect recent changes in SPNEGO and GSS-API code in the docs.
Update them with appropriate namings and remove visible spots for
GSS-Negotiate.