reset the authentication state to make it restart on the next connection.

This of course because NTLM is connection-oriented, whilst all other
authentication schemes are not.

NTLM request.

this then makes redirection tests work (as the new test 89)

it doesn't work. It works for me.

is over or not, as if it isn't we shall not begin any PUT or POST operation.

This cures bug report #805853, and test case 88 verifies it!

NOT free the existing hash entry when we try to add a new one that matches
an existing entry. We now instead free the new one, and make the parent
function use the old entry's struct instead.

ftp and an uninitialized pointer

sure to clear them before we run the tests as they interfere badly otherwise.

"Negotiate" authentication as well.

not used by any code in libcurl!

Problem tracked down by Bjorn Reese.

more in the same style as other curl source code. The only actual code change
is an added check after a malloc() call.

Kevin Fisk reported.

properly if no auth is available

CURLINFO_HTTPAUTH_AVAIL and CURLINFO_PROXYAUTH_AVAIL

2. made Curl_http_auth_act() reset 'authavail' unconditionally