c-ares version 1.24.0

This is a feature and bugfix release.

Features:
 o Add support for IPv6 link-local DNS servers.  Nameserver formats can now
   accept the %iface suffix, and a new ares_get_servers_csv() function was
   added to return servers that can contain the link-local interface name. [3]

Changes:
 o Unbundle GoogleTest for test cases.  Package maintainers will now need to
   require GoogleTest (GMock) as a build dependency if building tests. New
   GoogleTest versions require C++14 or later. [6]
 o Replace nameserver parsing code to use new memory-safe functions. [1]
 o Replace the sortlist parser with new memory-safe functions. [5]
 o Various warning fixes and dead code removal.

Bug Fixes:
 o Old Linux versions require POSIX_C_SOURCE or _GNU_SOURCE to compile with
   thread safety support. [2]
 o A non-responsive DNS server that caused timeouts wouldn't increment the
   failure count, this would lead to other servers not being tried.
   Regression introduced in 1.22.0. [4]
 o Some projects that depend on c-ares expect invalid parameter option values
   passed into ares_init_options() to simply be ignored.  This behavior has
   been restored. [7]
 o On linux getrandom() can fail if the kernel doesn't support the syscall,
   fall back to another random source. [8]
 o ares_cancel() when performing ares_gethostbyname() or ares_getaddrinfo()
   with AF_UNSPEC, if called after one address class was returned but before
   the other address class, it would return ARES_SUCCESS rather than
   ARES_ECANCELLED. [9]


Thanks go to these friendly people for their efforts and contributions:
  Brad House (@bradh352)
  Daniel Stenberg (@bagder)
(2 contributors)

References to bug reports and discussions on issues:
 [1] = https://github.com/c-ares/c-ares/pull/643
 [2] = https://github.com/c-ares/c-ares/issues/644
 [3] = https://github.com/c-ares/c-ares/pull/646
 [4] = https://github.com/c-ares/c-ares/pull/650
 [5] = https://github.com/c-ares/c-ares/pull/653
 [6] = https://github.com/c-ares/c-ares/pull/655
 [7] = https://github.com/c-ares/c-ares/commit/c982bf4
 [8] = https://github.com/c-ares/c-ares/pull/661
 [9] = https://github.com/c-ares/c-ares/pull/663


