Ipns name resolution

This branch is not yet complete, but before i move forward, the name resolution code (in namesys) needs some critiquing. There are also a decent number of bugfixes in this branch that i ran into while trying to get the code to a point where i could test ipns.
This may be out of the scope of this PR, but we might want

```
[]*ma.Multiaddr -> []ma.Multiaddr
```