gethostbyname() is not thread-safe.

This patch is not used in Windows. getaddrinfo() requires XP, and
gethostbyname is thread-safe with Winsock.
(cherry picked from commit 9fb933d3)

Conflicts:

	extras/contrib/src/Makefile

Please be more careful when you resolve conflicts! Prior to this patch,
contrib would not build on non-Windows.