Vista (_WIN32_WINNT >= 0x0600)

encrypt the control connection and use the data connection "plain".

it now will read the full data sent from servers. The SOCKS-related code was
also moved to the new lib/socks.c source file.

(http://curl.haxx.se/bug/view.cgi?id=1561470) that is said to crash when an
FTP upload fails with the multi interface. It did not, but I made a failed
upload still assume the control connection to be fine.

empty password or no password at all. Test case 278 and 279 were added to
verify.

FTPS

it basically was that we didn't remove the current connection from the pipe
list when following a redirect. Also in this commit: several cases of
additional debug code for debug builds helping to check and track down some
signs of run-time trouble.

currently fits in the cache, to make the cache work better especially for
pipelining cases but also for "mere" (persistent) connection re-use.

is still trying to resolve the host name, it seems that the ftp struct is not
yet initialized, but the removal action calls Curl_done() which calls
Curl_ftp_done. So we simply return success from there if no ftp pointer is
set.

Curl_signalPipeClose is now signalPipeClose().

all Win32 targets except CygWin. Cleanup.

FTP 3rd party transfers to that file for now until I have them sorted out.