JR Dalrymple / pf_interface_usage

It still works I think - I added the ability to list all the interfaces if you just omit the '-i' argument, example:

[jrdalrymple@mn-lx9 pf_interface_usage]$ ./check_snmp_usage.py -H 192.168.0.1
No interface specified - here are your options:
pflow0
vlan301
vlan300
vlan1
vlan202
pflog0
vlan204
vlan200
vlan201
lo0
vlan203
enc0
em0
em3
em2
em1
vlan105
pppoe0
pflow1

Don't know if I've committed since perfdata, but that's in and works

Need to add error checking for the -b argument and lots of other stuff, coming along though

Pulls in the data and prints out some useful junk - gotta add a couple of metrics to the tmp file so that it can handle situations where the snmp counter rolls or is reset

Next commit will have the bash script removed

It ocurred to me that saving a state file on the pf hosting machine is going to be dangerous and as such we're going a whole new route.

Just using plain old SNMP so it should work against non PF routers when I'm done making it more useful to the community at large.

copied useful parts of old check into new check and deleted old check

Next step is to dive into the when to reset logic