Avoid breaking configure due to CURL_FUNC_GETNAMEINFO_ARGTYPES failure, since at this point nothing depends on it.

justify checking for socklen_t in more than one function, the code
used to find a valid socklen_t replacement is simplified back. The
only function that will be used to find a socklen_t replacement is
getpeername, as it has been since revision 1.4 of curl/acinclude.m4

CURL_FUNC_GETNAMEINFO_ARGTYPES now also checks first argument.
All related changes taken to cares configuration scripts.

Fix compiler warning and compatibility issue with the type of the parameter used in getnameinfo() to receive the length of the sockaddr struct.

fixing a compiler warning in the append_scopeid() function.

ifdefs where . was used instead of _!

in mingw builds

macros accordingly.

Avoid warning 'x might be used uninitialized in this function'.

Use DNS__32BIT() and DNS__16BIT()  (How about BE machines?).
Display T_AAAA resource.