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.
probably shouldn't close channels this goroutine reads from, will cause things outside to panic. cancel signals should prob be sent via context, or other bands.