Add ability to show ipfw rules, that were added using new rule format (without generic rule body, just rule options)

[ae]

Summary

ipfw(8) command line parser accepts rule format, that contains only rule options in the body. But ipfw(8) opcodes parser expects only old format, when rule body contains all components of "proto from src to dst". This patch adds flag IPFW_RULE_JUSTOPTS, that is passed to the kernel, and back. So, ipfw(8) can determine what rule format was used and correctly show the rule.

[lev]

This patch helps with all my convoluted rules :-)