deprecated sunrpc and rpc/netdb.h

[Roland McGrath]

> We have that already (they can be compiled against glibc sunrpc
> or libtirpc):

Great!  How production-ready do you (or really, distro maintainers) think
this is?

I propose that we start by disabling or removing this code from glibc
(before getting serious about sunrpc itself).  If the replacements are
sufficiently production-ready, we can just remove it all now.  If not,
then we'll have to start with a --disable-nis configure switch to
disable building it all.