[MEDIUM] use getaddrinfo to resolve names if gethostbyname fail

[MEDIUM] use getaddrinfo to resolve names if gethostbyname fail

Function gethostbyname is deprecated since IEEE Std 1003.1-2008 and
was replaced by getaddrinfo (available since IEEE Std 1003.1-2004).
Contrary to gethostbyname, getaddrinfo is specified to support both
IPv4 and IPv4 addresses.
Since some libc doesn't handle getaddrinfo properly, constant
USE_GETADDRINFO must be defined at compile time to enable use of
getaddrinfo.