c-ares version 1.25.0

This is a maintenance release.

Changes:
 o AutoTools: rewrite build system to be lighter weight and fix issues in some
   semi-modern systems. It is likely this has broken building on some less
   common and legacy OSs, please report issues. [1]
 o Rewrite ares_strsplit() as a wrapper for ares__buf_split() for memory
   safety reasons. [4]
 o The ahost utility now uses ares_getaddrinfo() and returns both IPv4 and
   IPv6 addresses by default. [6]
 o OpenBSD: Add SOCK_DNS flag when creating socket. [12]

Bug Fixes:
 o Tests: Live reverse lookups for Google's public DNS servers no longer
   return results, replace with CloudFlare pubic DNS servers. [2]
 o MacOS legacy SDKs require sys/socket.h before net/if.h [3]
 o Connection failures should increment the server failure count first or a
   retry might be enqueued to the same server. [5]
 o On systems that don't implement the ability to enumerate network interfaces
   the stubs used the wrong prototype. [7]
 o Fix minor warnings and documentation typos. [8]
 o Fix support for older GoogleTest versions. [9]
 o getrandom() may require sys/random.h on some systems. [10]
 o Fix building tests with symbol hiding enabled. [11]

Thanks go to these friendly people for their efforts and contributions:
  Brad House (@bradh352)
  Daniel Stenberg (@bagder)
  Gregor Jasny (@gjasny)
  Martin Chang (@marty1885)
(4 contributors)

References to bug reports and discussions on issues:
 [1] = https://github.com/c-ares/c-ares/pull/674
 [2] = https://github.com/c-ares/c-ares/commit/1231aa7
 [3] = https://github.com/c-ares/c-ares/pull/673
 [4] = https://github.com/c-ares/c-ares/commit/88c444d
 [5] = https://github.com/c-ares/c-ares/commit/05181a6
 [6] = https://github.com/c-ares/c-ares/pull/669
 [7] = https://github.com/c-ares/c-ares/commit/eebfe0c
 [8] = https://github.com/c-ares/c-ares/pull/666
 [9] = https://github.com/c-ares/c-ares/commit/d186f11
 [10] = https://github.com/c-ares/c-ares/issues/665
 [11] = https://github.com/c-ares/c-ares/issues/664
 [12] = https://github.com/c-ares/c-ares/pull/659
