fix distcheck

Change-Id: I9eb45236f42518b798eaeb7a5577ca7f77fa477a
Backport nlist.[ch] changes from gdnsd

This gives us the ability to normalize truly ugly lists
  of networks from the JSON input, instead of failing on
  things like duplicates, merge-generated duplicates, and conflicts.

Change-Id: Ib1e6d95ac7ad687933a3e65cdab45ea02ec9e303