Ability for IPMI polling to be possible in NAT'ed environments

The other day I was working on adding a couple of servers to my Observium installation (we installed that day and haven't updated since, however, I have a different install somewhere else that is updated every day with SVN and this issue still persists) that are behind a public static IP (single).

I was already monitoring the servers via SNMP using port forwarding, but we had some troubles in the past with those servers with temperatures, so I decided to monitor them via IPMI as well.

I ended up port forwarding IPMI as well, and went to add it to Observium using the obvious (to me) method of IP:Port. When I went to poll to make sure it worked, to my eyes the IPMI poll didn't last as long as I expected (usually it takes a while). When debugging, I noticed that Observium currently doesn't handle this.

I modified my local install of Observium to make it support this scenario (multiple hosts behind NAT, IPMI polling). It may not be the best code written and could probably be written in another way, but hey, it works.