* net.cc: define _CYGWIN_IN_H and include resolv.h.
(realloc_ent): New function.
(dup_ent): Call realloc_ent.
(memcpy4to6): New function.
(dn_length1): New function.
(gethostby_helper): New function.
(gethostbyname2): New function.
* posix.sgml: Add gethostbyname2.
* include/cygwin/version.h: Bump API minor number.
* libc/minires.c (get_options): Look for "inet6" and apply bounds
to "retry" and "retrans".
(res_ninit): Set the default options at the beginning.
(dn_expand): Fix "off by one".
(res_ninit): Set id pseudo-randomly.
(res_nsend): Do not set close on exec. Initialize server from id.
Flush socket. Tighten rules for answer acceptance.
(res_nmkquery): Update id using current data.
(SUBLIBS): Add libresolv.a.
Add rule for libresolv.a.
* autoload.cc: Fix return code handling for IP Helper API in case
of being unable to load iphlpapi.dll.
(DnsQuery_A): Define.
(DnsRecordListFree): Define.
* cygwin.din: Export resolver functions.
* include/resolv.h: New header.
* include/arpa/nameser.h: New header.
* include/arpa/nameser_compat.h: New header.
* include/cygwin/version.h: Bump API minor number.
* libc/minires-os-if.c: New file.
* libc/minires.c: New file.
* libc/minires.h: New file.