dhcpd_compare v2

I wrote this a couple days ago. It's dreadfully slow (about 1/5 the speed of fridgei's dhcpd_compare) but prints the differences in a much more efficient and easy to read way, in my opinion. My question is: Do we want it?

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```none
real	97m11.664s
user	96m51.263s
sys	0m1.462s
```