-lresolv required in 2.99.48 on SunOS 4.1.3_U1

[Scott Ballantyne <sdb@redhotmomma.ssr.com>]

As I've mentioned before, the test for whether or not -lresolv is
needed is inadquate. Many systems (netbsd, sunos, solaris) have the
resolver routines in a shared library, but not the structure _res, for reasons explained in the Bind distribution, so I won't repeat them here.

So present test for -lresolv concludes -lresolv not needed, because
finds res_init() in shared lib, but then linking fails because no _res
struct found...

Please consider adding a _res.options = blah and a link as part of the
configure test.

sdb