Please review last commit in this branch

Please review my last commit in this pull request.

How I test that? I compiled whole library, and after that I do that:

```bash
NLCB=DEBUG ./nl-addr-list
```

What I expect? right, that all attributes will be printed as native values (not just hex)
But instead, I see VERY strange things: unknown attribute types and mismatched attribute typ and length. For example:

```
  [ATTR 03] 3 octets
U32=28524
 [ATTR 07] 92 octets
MSECS=120121645362496
```

How the U32 attribute may have length of 3? Or, say, MSECS attribute have length of 92 octets....

I think I'm do something wrong. But what?


P.S.
Also, you may just get my previous commit. It's tested :)