backend and are more robust against SIOCGIFCONF alignment issue.
now getifaddrs always takes care of the issue. (sync with kame tree)
use weak symbol just in case.
get{addr,name} info are implemented to have as little impact to existing
resolver code as possible, so they are NOT the optimal implementation.
They are at this moment not very thread safe (as they call
gethostby{name,addr}).
(shlib minor version)++, as new interfaces are added.
TODO: getipnodeby{name,addr} - which needs total reimplementation of
gethostby{name,addr}.
upgrade rcmd.c for multiple af support (needed for IPv6-ready rsh/rlogin)
