Rule Replacement

Modify the parser and add necessary functions to provide the command "nft replace rule <ruleid_spec> <new_rule>"

Example of use:

$ nft list ruleset -a
table ip filter {
    chain output {
        ip daddr 8.8.8.7 counter packets 0 bytes 0 # handle 3
    }
}
$ nft replace rule filter output handle 3 ip daddr 8.8.8.8 counter
$ nft list ruleset -a
table ip filter {
    chain output {
        ip daddr 8.8.8.8 counter packets 0 bytes 0 # handle 3
    }
}

Commits