fix the CONNECT authentication code with multi-pass auth methods (such as
NTLM) as it didn't previously properly ignore response-bodies - in fact it
stopped reading after all response headers had been received. This could
lead to libcurl sending the next request and reading the body from the first
request as response to the second request. (I also renamed the function,
which wasn't strictly necessary but...)

The best fix would to once and for all make the CONNECT code use the
ordinary request sending/receiving code, treating it as any ordinary request
instead of the special-purpose function we have now. It should make it
better for multi-interface too. And possibly lead to less code...

Added test case 265 for this. It doesn't work as a _really_ good test case
since the test proxy is too stupid, but the test case helps when running the
debugger to verify.

freeaddrinfo to the trace output

with CURLOPT_PROXY can use a http:// prefix and user + password. The user
and password fields are now also URL decoded properly.

Test case 264 added to verify.

address was not possible to use. It is now, but requires it written
RFC2732-style, within brackets - which incidently is how you enter numerical
IPv6 addresses in URLs. Test case 263 added to verify.

binary zeroes within the headers. They confused libcurl to do wrong so the
downloaded headers become incomplete. The fix is now verified with test case
262.

talking to sockfilt

can't be opened

to the docs.

"http://somehost?data" as it added a slash too much in the request ("GET
/?data/"...). Added test case 260 to verify.

or the test is skipped. Ideally, we should let this test case go over a few
frequently used IPv6 localhost aliases...

Added resolve.c to simply resolve a given host name

A) Normal non-proxy HTTP:

 - no more "Pragma: no-cache" (this only makes sense to proxies)

B) Non-CONNECT HTTP request over proxy:

 - "Pragma: no-cache" is used (like before)
 - "Proxy-Connection: Keep-alive" (for older style 1.0-proxies)

C) CONNECT HTTP request over proxy:

 - "Host: [name]:[port]"
 - "Proxy-Connection: Keep-alive"

but we could use having a look at ares/config.h when that is used

HTTP test server is a bit limited though, as it never responds to the POST
request until all data has been sent (and received)...