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.
alright, im thinking of making all the name stuff in a subpackage i.e. `cmd/ipfs/name` or `cmd/ipns`