Support fwmark and iif on the RoutingEntryRule

[Adam Dyess]

I would like the following advanced-routing-config
[{
    "type": "table",
    "table": "main"
},{
    "type": "table",
    "table": "Public"
},{
    "type": "rule",
    "fwmark": "1/0xF",
    "iif": "bond0",
    "table": "main",
    "priority": 110
},{
    "type": "rule",
    "fwmark": "1/0xF",
    "table": "Public"
    "priority": 111
}]

to create the rules:
ip rule add fwmark 1/0xF iif bond0 table main priority 110
ip rule add fwmark 1/0xF table Public priority 111

[Adam Dyess (addyess)]

this would enable routing decisions based on fwmark-ing and input interfaces