pass IPV6_MINMTU down to ip6_output.  need some clearup - maybe we should move the flag bit to in6p_outputopts.
pass IPV6_MINMTU down to ip6_output.  need some clearup -
maybe we should move the flag bit to in6p_outputopts.

MarginC/kame,MarginC/kame,MarginC/kame,MarginC/kame,MarginC/kame,MarginC/kame,MarginC/kame