1676. [port] Solaris 8 has if_nametoindex().
1675. [bug] match any returned scope when a scope is not specified
on non global scope address in resolv.conf.
1674. [bug] getaddrinfo() failed to set sin6_scope_id correctly
on some platforms.
- removed 'ifdef INET6' (libbind's getaddrinfo should always be buildable
with the INET6 part.)
- use EAI_NONAME instead of EAI_NODATA (this is an API issue. I'll raise
it at the group working on the API).
- use h_errno instead of __h_errno.
- clarification on using interface names as link IDs of IPv6 link-local
addresses. (not all OSes support this.)