add -m64 CFLAGS when targeting mingw64, add -m32/-m64 to LDFLAGS

mingw build: allow to pass custom CFLAGS

Better code reuse and consistency in calls to gss_import_name().

... instead of trying PASV, since PASV can't work with IPv6.

Reported-by: Vojtěch Král

... and make sure we can connect the data connection to a host name that
is longer than 48 bytes.

Also simplifies the code somewhat by re-using the original host name
more, as it is likely still in the DNS cache.

Original-Patch-by: Vojtěch Král
Bug: http://curl.haxx.se/bug/view.cgi?id=1468

Added support for a WITH_CARES option to be used when invoking nmake
via Makefile.vc. This option enables linking against both the DLL and
static versions of the c-ares libraries, as well as the debug and
release varients, depending on the value of DEBUG. The USE_ARES
preprocessor symbol is also defined.

Bug: http://curl.haxx.se/bug/view.cgi?id=1469
Reported-by: Thomas Klausner

...to avoid a session ID getting cached without certificate checking and
then after a subsequent _enabling_ of the check libcurl could still
re-use the session done without cert checks.

Bug: http://curl.haxx.se/docs/adv_20150108A.html
Reported-by: Marc Hesse

Bug: http://curl.haxx.se/docs/adv_20150108B.html

Bug: http://curl.haxx.se/docs/adv_20150108B.html
Reported-by: Andrey Labunets

Also, remove the log output of the resolved name is NOT in the cache in
the spirit of only telling when something is actually happening.

Reported-by: Michael Osipov

Otherwise, the fixes in the previous commits would only be applicable
to IDN and SSPI based builds and not others such as OpenSSL with LDAP
enabled.

Use 'TCHAR *' for local attribute variable rather than 'char *'.

Use 'TCHAR *' for local DN variable rather than 'char *'.

Due to the recent modifications this function is no longer used.

ldap.c:98: warning: extra tokens at end of #endif directive

ldap.c:802: warning: comparison between signed and unsigned integer
            expressions

The unescapped DN was not freed after a successful character conversion.

ldap.c:738: error: macro "LDAP_TRACE" passed 2 arguments, but takes
            just 1

ldap.c:89: warning: extra tokens at end of #endif directive