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.
don't think it's in new master, but i _think_ @perfmode wanted to do a deferred cancel to make it easier to bail out of this function safely.