systems which support external, undefined, symbols in shared libraries.

if library initialization has not been performed calling ares_library_init().

  out that the cookie parser would leak memory when it parses cookies that are
  received with domain, path etc set multiple times in the same header. While
  such a cookie is questionable, they occur in the wild and libcurl no longer
  leaks memory for them. I added such a header to test case 8.

forced to use nmake for VC builds early so that its also used for ares even if we find a GNU make first in path; simplified curl make call.

C-Ares and IPv6 is no longer a bad combo.

tests on machines that have broken DNS configurations (such as
those configured to use OpenDNS).

changed ssh.c to use HAVE_LIBSSH2_SESSION_BLOCK_DIRECTION define provided by libssh2.h; removed related define block from ssh.h.

  https://bugzilla.redhat.com/show_bug.cgi?id=427966 which was libcurl closing
  a bad file descriptor when closing down the FTP data connection.  Caolan
  McNamara seems to be the original author of it.

c-ares can work even with no advapi32.dll at all.

Made OS400 version compilable again